Re: [SlimDevices: Audiophiles] Stereophile Review II: What conclusion can be drawn from the Measurements?
So guys is the touch any good -- bigblackdog bigblackdog's Profile: http://forums.slimdevices.com/member.php?userid=37719 View this thread: http://forums.slimdevices.com/showthread.php?t=82050 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] Stereophile Review II: What conclusion can be drawn from the Measurements?
bigblackdog;585761 Wrote: So guys is the touch any good For its 300$, serving as a single standalone unit - it is good If you're audiophile, you shall listen to one before you jump on.. -- michael123 michael123's Profile: http://forums.slimdevices.com/member.php?userid=23745 View this thread: http://forums.slimdevices.com/showthread.php?t=82050 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] Stereophile Review II: What conclusion can be drawn from the Measurements?
Stereoeditor;585609 Wrote: My apologies for not responding sooner. I was indeed busy, as the recent RMAF knocked a hole in my magazine work schedule that it takes a while to fill. It is going to depend on your playback equipment and the level at which you listen. A typical inexpensive DVD player that has no more than 16 bits worth of dynamic range is not going to allow a listener to distinguish between 16- and 24-bit audio. Similarly, if you play your music at low levels, the extra resolution afforded by 16-bit audio is going to drop below the threshold of your hearing. As to the absolute threshold, I can certainly hear the difference between 16- and 20-bit files with a state-of-the-art DAC. But between 20 and 24? I am not sure I could reliably detect that difference, though some listeners I respect, like mastering engineer Bob Katz, have discussed audible differences in dither with 24-bit data, which will only be producing measurable differences at the 24th bit level. That's what I would have recommended. John Atkinson Editor, Stereophile Thanks very much. I am very grateful for you taking the time. I am a big fan of your reviews and measurement reports which I think provide a very important balance in your magazine. I note re the resolution issue that the Society of Sound website displays the following quote: Malcolm Hawksford, Professor of Psychoacoustics at Essex University, reckons that, CDs digital specification was almost good enough for audiophile music reproduction. It was near the limit, but in my view probably a bit marginal. Ideally, at least 20-bit resolution at 60 kHz sampling frequency would have been better. -- adamdea adamdea's Profile: http://forums.slimdevices.com/member.php?userid=37603 View this thread: http://forums.slimdevices.com/showthread.php?t=82050 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] Stereophile Review II: What conclusion can be drawn from the Measurements?
adamdea;585139 Wrote: I am coming to terms with my disappointment at not receiving a reply from JA, although I know he's very busy. My apologies for not responding sooner. I was indeed busy, as the recent RMAF knocked a hole in my magazine work schedule that it takes a while to fill. . I wonder if you could express a view as to what the cut off threshold for resolution (as you measure it) where a higher level would probably make no discernible difference when playing 24 bit audio files. It is going to depend on your playback equipment and the level at which you listen. A typical inexpensive DVD player that has no more than 16 bits worth of dynamic range is not going to allow a listener to distinguish between 16- and 24-bit audio. Similarly, if you play your music at low levels, the extra resolution afforded by 16-bit audio is going to drop below the threshold of your hearing. As to the absolute threshold, I can certainly hear the difference between 16- and 20-bit files with a state-of-the-art DAC. But between 20 and 24? I am not sure I could reliably detect that difference, though some listeners I respect, like mastering engineer Bob Katz, have discussed audible differences in dither with 24-bit data, which will only be producing measurable differences at the 24th bit level. I just thought I would let him (if he's reading) and you (Phil) know that i have taken the plunge and bought the Principles of Digital Audio by Pohlmann which I will definitely have finished by the time Hell freezes over. That's what I would have recommended. John Atkinson Editor, Stereophile -- Stereoeditor Stereoeditor's Profile: http://forums.slimdevices.com/member.php?userid=40770 View this thread: http://forums.slimdevices.com/showthread.php?t=82050 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] Stereophile Review II: What conclusion can be drawn from the Measurements?
adamdea;582298 Wrote: Dear John It is a great privilege to have you post a reply on this thread (even if not to me!). I wondered if i could try you patience by asking a couple of questions .. Also can you recommend a good book an the basic principles of digital audio. I am coming to terms with my disappointment at not receiving a reply from JA, although I know he's very busy. I just thought I would let him (if he's reading) and you (Phil) know that i have taken the plunge and bought the Principles of Digital Audio by Pohlmann which I will definitely have finished by the time Hell freezes over. -- adamdea adamdea's Profile: http://forums.slimdevices.com/member.php?userid=37603 View this thread: http://forums.slimdevices.com/showthread.php?t=82050 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] Stereophile Review II: What conclusion can be drawn from the Measurements?
adamdea;585139 Wrote: I am coming to terms with my disappointment at not receiving a reply from JA, although I know he's very busy. I just thought I would let him (if he's reading) and you (Phil) know that i have taken the plunge and bought the Principles of Digital Audio by Pohlmann which I will definitely have finished by the time Hell freezes over. Enjoy :-) -- Phil Leigh You want to see the signal path BEFORE it gets onto a CD/vinyl...it ain't what you'd call minimal... Touch(wired/XP) - TACT 2.2X (Linear PSU) + Good Vibrations S/W - MF Triplethreat(Audiocom full mods) - Linn 5103 - Aktiv 5.1 system (6x LK140's, ESPEK/TRIKAN/KATAN/SEIZMIK 10.5), Pekin Tuner, Townsend Supertweeters, Blue Jeans Digital,Kimber Speaker Chord Interconnect cables Kitchen Boom, Outdoors: SB Radio, Harmony One remote for everything. Phil Leigh's Profile: http://forums.slimdevices.com/member.php?userid=85 View this thread: http://forums.slimdevices.com/showthread.php?t=82050 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] Stereophile Review II: What conclusion can be drawn from the Measurements?
Dont get to too hung up on one review. Everyone has their bias. Combine reviews to get a better feel for the house sound you are looking for. Go for reputation. Squeezebox stuff is known for getting the bits to the DAC. You have to go from there. I would trust Squeezebox with my bits anyday! What I will do with them from there is the big question. Now, for me, the Transporter is doing me good. I'm curious about what is going on with the ESS chips at 32bit. Its all about implementation. Best bang for buck right now is probably the Wyred4sound. My opinion as of 10/19/10. Tomorrow is a new day in audio! -- earwaxer9 System: modified Winsome Labs Mouse, modified Maggie MMG's, Transporter, HSU sub 12, MSB DAC to 500 watt sub slave amp, JPS labs power cords, Silver audio interconnect, Audioquest Granite speaker cable. earwaxer9's Profile: http://forums.slimdevices.com/member.php?userid=39527 View this thread: http://forums.slimdevices.com/showthread.php?t=82050 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] Stereophile Review II: What conclusion can be drawn from the Measurements?
Hi: 24bit=144dBThis can't at the moment be converted to analog. Max dynamic out of a Current DAC is: 132dB (PCM1794 / PCM1792 in mono and balanced configuration). I once asked a Burr Brown sales manager why they annonced 24bit whaen it not was possible to convert this to analog. He returned with a smile and said. 24 maketing bit. -- Caad Caad's Profile: http://forums.slimdevices.com/member.php?userid=9350 View this thread: http://forums.slimdevices.com/showthread.php?t=82050 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] Stereophile Review II: What conclusion can be drawn from the Measurements?
cliveb;579311 Wrote: Excuse me for coming in a bit late but I wanted to comment on this. Resolution and precision are two sides of the same coin. Here's an analogy. Take a 12 ruler - what is the smallest sized object you can confidently measure the size of? That's the resolution of your 12 ruler. Now measure something that's about 6 long - what's the accuracy with which you can measure its exact length? That's the precision. Can you see that both are constrained by the physical characteristics of the ruler itself, and are fundamentally the same thing? If you use a micrometer instead, you'll be able to both measure smaller objects (better resolution) and more accurately the size of relatively large objects (better precision). We can liken the 12 ruler to 8 bit digital audio and the micrometer to 16 bit audio. When it comes to audio, both resolution and precision are limited by the same thing: bit-depth (digital) or noise floor (analogue). They are just different ways of inaccurately measuring the voltage of a music signal. In particular, analogue does not have unlimited precision, because although (unlike digital) the voltage it delivers can be any arbitrary value, the noise floor means that the actual voltage is only an approximation. If the voltage should be 1V, an anlogue system might deliver anywhere between 0.999V or 1.001V, and you have no way of knowing what it should really be. It's a bit like you using that 12 ruler to measure an object is exactly 6 long - due to its lack of precision you are only in a position to say that it's somewhere between 5.95 and 6.05 Thanks. This is very helpful too. I am afraid that having got my tiny mind a little way into this problem a couple of weeks ago, I then got too distracted by the tedious business of earning a living etc to pose the next incisive question which I have now forgotten. I realised at about the same time that the area where i migth be getting my knickers in a twist was not in the mathematical properties of binary numbers but the way that noise works in an electrical system. What you have said about the noise floor very elegantly illustrates a confusion i had had about whether the noise floor would always be added to the signal in an analog system or whether it could ever be swamped.(ie cease to have any impact at all when the signal was strong enough.) I understand the answer to be no. It seems that the range of amplitude values expressed by an analog system should be perfectly reproducible by a digital system with dither added, provided that the digital system had sufficent resoltuion to resolve a noise below the noise floor of the analog system. I wonder whether the ruler analogy a breaks down though once one looks at a sequence of samples. It occurs to me that if the noise is random then one could still in principle detect the difference between two signals the difference between which is lower than the noise floor. [Please forgive me if I have got the wrong end of the stick again, but I am eager to learn] If one had a signal of 1v and noise with a peak level of +/- 0.1v then the output would range between 0.9V and 1.1V. If the signal became 1.05 V the output would range between 0.95 and 1.15. If we were dealing with a large number of samples for each signal one could presumably infer the existence of the change in the signals and even calculate the two signals by averaging in each case. We could identify the two outputs as two distinct signals with specified noise. This seems like the sort of thing people do in statistics. It therefore follows (?) that it is possible in principle to distinguish in an analog system between two signals whose amplitude varies by less than the noise floor. [I don't think you can do that with an equivalent digital system with quantisation noise equivalent to the analog noise floor.] I appreciate that this only works with a sufficiently large number of identical signals, and suspect that i am going to be told that it is irrelevant in an audio context. -- adamdea adamdea's Profile: http://forums.slimdevices.com/member.php?userid=37603 View this thread: http://forums.slimdevices.com/showthread.php?t=82050 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] Stereophile Review II: What conclusion can be drawn from the Measurements?
Stereoeditor;580202 Wrote: You can find this graph at http://stereophile.com/hirezplayers/cary_audio_design_classic_cd_303t_professional_sacd_player/index5.html . John Atkinson Editor, Stereophile Dear John It is a great privilege to have you post a reply on this thread (even if not to me!). I wondered if i could try you patience by asking a couple of questions I. I wonder if you could express a view as to what the cut off threshold for resolution (as you measure it) where a higher level would probably make no discernible difference when playing 24 bit audio files. I note that the AYRE DAC which is regarded by Stereophile as a state of the art DAC was measured by you as having 18 bit resolution. I have noticed that some other devices have measured higher (including the transporter but also as I recall the MF X DAC v3. However i appreciate that you have changed measuring equipment so some comparisons may be invalid )Clearly this is not the only determining factor of sound quality, but do you think it would make any perceivable difference ceteris paribus if the resolution of the Ayre DAC were higher. II. Do you ever measure the outputs of digital transports? (I can't remember seeing such a measurement). If so what do you (or would you) measure. What sort of factors affect the sound quality of a transport outputting to a decently designed modern DAc via SpDIF. III. Many contributors to this forum have expressed surprise at the Log Touch'es class D stereophile rating- this is presumably based on the analogue outs(?) Could you venture an opinion as to how it would compare with a conventional CD player outputting to a decent DAC. Obviously the quality would depend with the DAc, but given the DAC Also can you recommend a good book an the basic principles of digital audio. -- adamdea adamdea's Profile: http://forums.slimdevices.com/member.php?userid=37603 View this thread: http://forums.slimdevices.com/showthread.php?t=82050 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] Stereophile Review II: What conclusion can be drawn from the Measurements?
adamdea;582294 Wrote: Thanks. This is very helpful too. I am afraid that having got my tiny mind a little way into this problem a couple of weeks ago, I then got too distracted by the tedious business of earning a living etc to pose the next incisive question which I have now forgotten. I realised at about the same time that the area where i migth be getting my knickers in a twist was not in the mathematical properties of binary numbers but the way that noise works in an electrical system. What you have said about the noise floor very elegantly illustrates a confusion i had had about whether the noise floor would always be added to the signal in an analog system or whether it could ever be swamped.(ie cease to have any impact at all when the signal was strong enough.) I understand the answer to be no. It seems that the range of amplitude values expressed by an analog system should be perfectly reproducible by a digital system with dither added, provided that the digital system had sufficent resoltuion to resolve a noise below the noise floor of the analog system. I wonder whether the ruler analogy a breaks down though once one looks at a sequence of samples. It occurs to me that if the noise is random then one could still in principle detect the difference between two signals the difference between which is lower than the noise floor. [Please forgive me if I have got the wrong end of the stick again, but I am eager to learn] If one had a signal of 1v and noise with a peak level of +/- 0.1v then the output would range between 0.9V and 1.1V. If the signal became 1.05 V the output would range between 0.95 and 1.15. If we were dealing with a large number of samples for each signal one could presumably infer the existence of the change in the signals and even calculate the two signals by averaging in each case. We could identify the two outputs as two distinct signals with specified noise. This seems like the sort of thing people do in statistics. It therefore follows (?) that it is possible in principle to distinguish in an analog system between two signals whose amplitude varies by less than the noise floor. [I don't think you can do that with an equivalent digital system with quantisation noise equivalent to the analog noise floor.] I appreciate that this only works with a sufficiently large number of identical signals, and suspect that i am going to be told that it is irrelevant in an audio context. Just to recap - quantization noise is an error in the lowest 1/2 bit (remember it's a rounding error)and so is very tiny in a 16-bit scenario where the signal level of the recording is at minimum -40 to -50dB. You still seem to be searching for something that isn't to be found - i.e. some kind of proof that in 16-bit audio there are tiny variations in level that cannot be captured. The fact is such variations are VERY tiny and would always be swamped by variations in the real noise floor of the recording and replay system, never mind any ACTUAL music that might be playing. Remember that one sample contains data representing all sounds simultaneously occurring - it's the cumulative total of all contributory sine/cosine waves. Since dither is introduced during the recording/mastering process to effectively hide the quantization noise, the whole point is moot anyway :-) If you want to hear quantization noise, record a sine wave in 16-bit at -90dB and play it back with a LOT of gain and no dither. Digital audio (done properly) simply doesn't have the intrinsic flaw that too many folks interpret from looking at all of those nasty little staircase sine waves dotted around the Internet. Now, if you are in the habit of listening to -90dB sine waves on their own (you sure won't hear them alongside ANYTHING else!) , I urge you to upgrade to a 20+bit recording/replay chain :-) -- Phil Leigh You want to see the signal path BEFORE it gets onto a CD/vinyl...it ain't what you'd call minimal... Touch(wired/XP) - TACT 2.2X (Linear PSU) + Good Vibrations S/W - MF Triplethreat(Audiocom full mods) - Linn 5103 - Aktiv 5.1 system (6x LK140's, ESPEK/TRIKAN/KATAN/SEIZMIK 10.5), Pekin Tuner, Townsend Supertweeters, Blue Jeans Digital,Kimber Speaker Chord Interconnect cables Kitchen Boom, Outdoors: SB Radio, Harmony One remote for everything. Phil Leigh's Profile: http://forums.slimdevices.com/member.php?userid=85 View this thread: http://forums.slimdevices.com/showthread.php?t=82050 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] Stereophile Review II: What conclusion can be drawn from the Measurements?
adamdea;582298 Wrote: Dear John It is a great privilege to have you post a reply on this thread (even if not to me!). I wondered if i could try you patience by asking a couple of questions I. I wonder if you could express a view as to what the cut off threshold for resolution (as you measure it) where a higher level would probably make no discernible difference when playing 24 bit audio files. I note that the AYRE DAC which is regarded by Stereophile as a state of the art DAC was measured by you as having 18 bit resolution. I have noticed that some other devices have measured higher (including the transporter but also as I recall the MF X DAC v3. However i appreciate that you have changed measuring equipment so some comparisons may be invalid )Clearly this is not the only determining factor of sound quality, but do you think it would make any perceivable difference ceteris paribus if the resolution of the Ayre DAC were higher. II. Do you ever measure the outputs of digital transports? (I can't remember seeing such a measurement). If so what do you (or would you) measure. What sort of factors affect the sound quality of a transport outputting to a decently designed modern DAc via SpDIF. III. Many contributors to this forum have expressed surprise at the Log Touch'es class D stereophile rating- this is presumably based on the analogue outs(?) Could you venture an opinion as to how it would compare with a conventional CD player outputting to a decent DAC. Obviously the quality would depend with the DAc, but given the DAC Also can you recommend a good book an the basic principles of digital audio. I'm sure John will be along soon, but in the meantime, there is only 1 thing to measure in a s/pdif signal: Does it have nice, clean-edged waveforms, as square(ish) as possible with an accurate clock within it? (OK I suppose that is 2 things...) Any noise/rfi/cable or termination reflection would make the waveform less perfectly square... Any imperfections in the waveform at the DAC end make it harder for the DAC to recover the clock accurately due to increased uncertainty regarding the transition points... JITTER! -- Phil Leigh You want to see the signal path BEFORE it gets onto a CD/vinyl...it ain't what you'd call minimal... Touch(wired/XP) - TACT 2.2X (Linear PSU) + Good Vibrations S/W - MF Triplethreat(Audiocom full mods) - Linn 5103 - Aktiv 5.1 system (6x LK140's, ESPEK/TRIKAN/KATAN/SEIZMIK 10.5), Pekin Tuner, Townsend Supertweeters, Blue Jeans Digital,Kimber Speaker Chord Interconnect cables Kitchen Boom, Outdoors: SB Radio, Harmony One remote for everything. Phil Leigh's Profile: http://forums.slimdevices.com/member.php?userid=85 View this thread: http://forums.slimdevices.com/showthread.php?t=82050 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] Stereophile Review II: What conclusion can be drawn from the Measurements?
Phil Leigh;582320 Wrote: Just to recap - quantization noise is an error in the lowest 1/2 bit (remember it's a rounding error)and so is very tiny in a 16-bit scenario where the signal level of the recording is at minimum -40 to -50dB. You still seem to be searching for something that isn't to be found - i.e. some kind of proof that in 16-bit audio there are tiny variations in level that cannot be captured. The fact is such variations are VERY tiny and would always be swamped by variations in the real noise floor of the recording and replay system, never mind any ACTUAL music that might be playing. Remember that one sample contains data representing all sounds simultaneously occurring - it's the cumulative total of all contributory sine/cosine waves. Since dither is introduced during the recording/mastering process to effectively hide the quantization noise, the whole point is moot anyway :-) If you want to hear quantization noise, record a sine wave in 16-bit at -90dB and play it back with a LOT of gain and no dither. Digital audio (done properly) simply doesn't have the intrinsic flaw that too many folks interpret from looking at all of those nasty little staircase sine waves dotted around the Internet. Now, if you are in the habit of listening to -90dB sine waves on their own (you sure won't hear them alongside ANYTHING else!) , I urge you to upgrade to a 20+bit recording/replay chain :-) Honestly Phil, I just like to understand things. It may amuse you to know that i have been quizzing a mathematician friend of mine who knows quite a lot about information theory (but not audio) about the effect of noise on digital information. He ended saying- now that's not theory that's practice. Incidentally on the 20 bit track I have been fiddling with Dbpoweramp making 24 bit recordings of HDCDs which i have never been able to decode before. Now would I right in thinking that these should sound about as good as 24 bit files bearing in mind your scepticism about anything more than 18 bit resolution. Of course there's the sample rate too but Now it would be an interesting conclusion that all the 2 channel audio world ever needed was HDCD. Almost all Linn recordings are downloadable HDcd coded at a much lower price than the 24 bit files. Ditto reference recordings on HDtracks. -- adamdea adamdea's Profile: http://forums.slimdevices.com/member.php?userid=37603 View this thread: http://forums.slimdevices.com/showthread.php?t=82050 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] Stereophile Review II: What conclusion can be drawn from the Measurements?
adamdea;582335 Wrote: Honestly Phil, I just like to understand things. It may amuse you to know that i have been quizzing a mathematician friend of mine who knows quite a lot about information theory (but not audio) about the effect of noise on digital information. He ended saying- now that's not theory that's practice. Incidentally on the 20 bit track I have been fiddling with Dbpoweramp making 24 bit recordings of HDCDs which i have never been able to decode before. Now would I right in thinking that these should sound about as good as 24 bit files bearing in mind your scepticism about anything more than 18 bit resolution. Of course there's the sample rate too but Now it would be an interesting conclusion that all the 2 channel audio world ever needed was HDCD. Almost all Linn recordings are downloadable HDcd coded at a much lower price than the 24 bit files. Ditto reference recordings on HDtracks. ...and I'm trying (probably badly) to help! HDCD is complex. The extra information buried in the bottom bit is used for various purposes and some of them really have no direct analogue to proper 20/24-bit recording. All my HDCD's (60, including various excellent Linn discs) have been transcoded to 24-bit files with DBP and I think they all sound great and better than the straight (non-HDCD) playback of the original 16-bit file. They used to sound great when I had an HDCD CD player. However, given the choice I'd rather have a 24/96 DVD-A (I have the HDCD and DVD-A versions of the King Crimson albums for example). Now, these aren't identical mix masters but the DVD-A's sound better to me. -- Phil Leigh You want to see the signal path BEFORE it gets onto a CD/vinyl...it ain't what you'd call minimal... Touch(wired/XP) - TACT 2.2X (Linear PSU) + Good Vibrations S/W - MF Triplethreat(Audiocom full mods) - Linn 5103 - Aktiv 5.1 system (6x LK140's, ESPEK/TRIKAN/KATAN/SEIZMIK 10.5), Pekin Tuner, Townsend Supertweeters, Blue Jeans Digital,Kimber Speaker Chord Interconnect cables Kitchen Boom, Outdoors: SB Radio, Harmony One remote for everything. Phil Leigh's Profile: http://forums.slimdevices.com/member.php?userid=85 View this thread: http://forums.slimdevices.com/showthread.php?t=82050 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] Stereophile Review II: What conclusion can be drawn from the Measurements?
adamdea;582335 Wrote: Almost all Linn recordings are downloadable HDcd coded at a much lower price than the 24 bit files. Ditto reference recordings on HDtracks. Not exactly. Many HDCDs just decode to 17bits of audio. Some even to 17bits but at a peak level below -6dB so they are 16bit technically. Some use a few bits mor only in some places and very few ones seem to use more bits all the time. Being HDCD sometimes only means it was mixed on HDCD capable hardware and the dithernoise is based on it, not more. Edit: wrote that while Phil answered, hope it is someething nonetheless. -- Wombat Transporter - RG142 - Avantgarde based monoblocks - Sommer SPK240 - self-made speakers Wombat's Profile: http://forums.slimdevices.com/member.php?userid=4113 View this thread: http://forums.slimdevices.com/showthread.php?t=82050 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] Stereophile Review II: What conclusion can be drawn from the Measurements?
Wombat;582341 Wrote: Not exactly. Many HDCDs just decode to 17bits of audio. Some even to 17bits but at a peak level below -6dB so they are 16bit technically. Some use a few bits mor only in some places and very few ones seem to use more bits all the time. Being HDCD sometimes only means it was mixed on HDCD capable hardware and the dithernoise is based on it, not more. Edit: wrote that while Phil answered, hope it is something usefull nonetheless. Wombat - This is all true - after all, there is only so much information you can overload that bottom half-a-bit with... :-) -- Phil Leigh You want to see the signal path BEFORE it gets onto a CD/vinyl...it ain't what you'd call minimal... Touch(wired/XP) - TACT 2.2X (Linear PSU) + Good Vibrations S/W - MF Triplethreat(Audiocom full mods) - Linn 5103 - Aktiv 5.1 system (6x LK140's, ESPEK/TRIKAN/KATAN/SEIZMIK 10.5), Pekin Tuner, Townsend Supertweeters, Blue Jeans Digital,Kimber Speaker Chord Interconnect cables Kitchen Boom, Outdoors: SB Radio, Harmony One remote for everything. Phil Leigh's Profile: http://forums.slimdevices.com/member.php?userid=85 View this thread: http://forums.slimdevices.com/showthread.php?t=82050 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] Stereophile Review II: What conclusion can be drawn from the Measurements?
The review is 'now up' (http://stereophile.com/computeraudio//logitech_squeezebox_touch_network_music_player/index5.html) on the Stereophile site. -- Daverz Daverz's Profile: http://forums.slimdevices.com/member.php?userid=32335 View this thread: http://forums.slimdevices.com/showthread.php?t=82050 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] Stereophile Review II: What conclusion can be drawn from the Measurements?
Phil Leigh;578530 Wrote: 1) 24-bit PRECISION. The ambient noise will be represented by word values built from the sum of the lowest 14-15 bits. 2) 16-bit PRECISION. The ambient noise will be represented by word values built from the sum of the lowest 6-7 bits. I'm afraid this is a little more complicated than that. The spectrum of noise from 14/15 bits will be far more pleasing on the ear than the spectrum of noise from 6/7 bits. Regardless to a point of the total number of bits. It was not uncommon in the early days of CDs for random noise to be added to the lower bits as noise as it's more appealing to the ear than quantisation distortion which is higher as the number of overall bits is decreased. -- Waldo Pepper Waldo Pepper's Profile: http://forums.slimdevices.com/member.php?userid=39029 View this thread: http://forums.slimdevices.com/showthread.php?t=82050 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] Stereophile Review II: What conclusion can be drawn from the Measurements?
Soulkeeper;578864 Wrote: I don't know the answer to that, but it seems to me that your example has a DC bias. If we define origo (zero) to the middle then the signal would probably vary between 128 and -128, or 32 and -32. (Or if you define origo (zero) to be all bits=zero then 128 would be the middle (silence), and the signal would vary between 256 and 0, or 160 and 96.) Or perhaps I misunderstood you completely. :P It's often easier to have a DC bias from an electronics point of view as it makes the understanding a tadge easier. However on an 8 bit system it would be +128 and -127 as the left hand bit represents the sign bit and +128 to -128 would require 9 bits (the extra to represent the -sign on an 8 bit word). You are on the right tracks though in your understanding. -- Waldo Pepper Waldo Pepper's Profile: http://forums.slimdevices.com/member.php?userid=39029 View this thread: http://forums.slimdevices.com/showthread.php?t=82050 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] Stereophile Review II: What conclusion can be drawn from the Measurements?
adamdea;578884 Wrote: If you reduced by 24 db would you get 8 8 8 9 8 8 8 8 8 7 8 8 8. (I said 24 db because you said it was a 6 db reduction in your example but I confess I don't understand the 6 db equivalence. I just mean getting quieter to the point where the peak becomes 9 and the trough 7) 6dB is often used as as +6d dB is a double in signal level and a -6dB is a halving in signal level. The dB is derived from the logarithmic scaling of signal levels. Decibel scale is logarithmic (to understand logs you should have paid more attention at school::) A decibel is 10th of a bell, but is a measure of power which is proportional to voltage squared that comes out as 10 * it's square ie 10*2=20. (school stuff:) 20 log 2(twice the amplitude) = +6db 20 log 1/2 (half the amplitude) = -6dB. So the OP using 6db plus or minus is a good analogy. -- Waldo Pepper Waldo Pepper's Profile: http://forums.slimdevices.com/member.php?userid=39029 View this thread: http://forums.slimdevices.com/showthread.php?t=82050 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] Stereophile Review II: What conclusion can be drawn from the Measurements?
Phil Leigh;579230 Wrote: OK - I'll try. 1: a true 24-bit ADC ( that doesn't exist) Rubbish! It needs very good electronic devices ahead of them. Burr Brown make them and a couple of balanced MP402 transistors in front and we are talking nanovolt resolution. Widely used in the medical proffesion of measuring brain and heart impulses that are way down in the microvolt ranges. -- Waldo Pepper Waldo Pepper's Profile: http://forums.slimdevices.com/member.php?userid=39029 View this thread: http://forums.slimdevices.com/showthread.php?t=82050 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] Stereophile Review II: What conclusion can be drawn from the Measurements?
Waldo Pepper;580924 Wrote: Rubbish! It needs very good electronic devices ahead of them. Burr Brown make them and a couple of balanced MP402 transistors in front and we are talking nanovolt resolution. Widely used in the medical proffesion of measuring brain and heart impulses that are way down in the microvolt ranges. Look - it doesn't exist in an AUDIO context. I wasn't talking about scientific/medical devices. This was covered in an earlier thread. -- Phil Leigh You want to see the signal path BEFORE it gets onto a CD/vinyl...it ain't what you'd call minimal... Touch(wired/XP) - TACT 2.2X (Linear PSU) + Good Vibrations S/W - MF Triplethreat(Audiocom full mods) - Linn 5103 - Aktiv 5.1 system (6x LK140's, ESPEK/TRIKAN/KATAN/SEIZMIK 10.5), Pekin Tuner, Townsend Supertweeters, Blue Jeans Digital,Kimber Speaker Chord Interconnect cables Kitchen Boom, Outdoors: SB Radio, Harmony One remote for everything. Phil Leigh's Profile: http://forums.slimdevices.com/member.php?userid=85 View this thread: http://forums.slimdevices.com/showthread.php?t=82050 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] Stereophile Review II: What conclusion can be drawn from the Measurements?
Waldo Pepper;580913 Wrote: I'm afraid this is a little more complicated than that. The spectrum of noise from 14/15 bits will be far more pleasing on the ear than the spectrum of noise from 6/7 bits. Regardless to a point of the total number of bits. It was not uncommon in the early days of CDs for random noise to be added to the lower bits as noise as it's more appealing to the ear than quantisation distortion which is higher as the number of overall bits is decreased. This is a hypothetical example. As is the entire thread... -- Phil Leigh You want to see the signal path BEFORE it gets onto a CD/vinyl...it ain't what you'd call minimal... Touch(wired/XP) - TACT 2.2X (Linear PSU) + Good Vibrations S/W - MF Triplethreat(Audiocom full mods) - Linn 5103 - Aktiv 5.1 system (6x LK140's, ESPEK/TRIKAN/KATAN/SEIZMIK 10.5), Pekin Tuner, Townsend Supertweeters, Blue Jeans Digital,Kimber Speaker Chord Interconnect cables Kitchen Boom, Outdoors: SB Radio, Harmony One remote for everything. Phil Leigh's Profile: http://forums.slimdevices.com/member.php?userid=85 View this thread: http://forums.slimdevices.com/showthread.php?t=82050 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] Stereophile Review II: What conclusion can be drawn from the Measurements?
Stereoeditor;580201 Wrote: Just saw this question. If you are talking about the undithered tone at -90.31dBFS I show in all my DAC measurements, I use this signal, not because it will be typical of music, but because it is diagnostic for DAC problems. In 2s-complement PCM encoding as used on CD, the change in level from digital 0 to +1 LSB actually involves all bits in the 16-bit word changing value. By contrast, the change from 0 to -1 LSB involves just the LSB changing value. So you can immediately see from the symmetry of the waveform, and how well-defined the 3 voltage levels are, whether or not the DAC is sufficiently monotonic and the analog noisefloor is sufficiently low to allow those data to be correctly decoded. In other words, it's a thumbnail indicator of DAC quality. In general, the test is not as useful in these days of sigma-delta DACs as it was when all we had were multi-bit DACs. However, you still come across pathological designs that fail to reproduce this signal properly - see, for example, fig.8 in the Cary review in the September 2010 issue of Stereophile. John Atkinson Editor, Stereophile John - thanks - very interesting - please bear in mind I haven't read the article in question so I was basing my remarks on an interpretation of what others had said (!?)... Hopefully I will get to read the article at some point. regards Phil -- Phil Leigh You want to see the signal path BEFORE it gets onto a CD/vinyl...it ain't what you'd call minimal... Touch(wired/XP) - TACT 2.2X (Linear PSU) + Good Vibrations S/W - MF Triplethreat(Audiocom full mods) - Linn 5103 - Aktiv 5.1 system (6x LK140's, ESPEK/TRIKAN/KATAN/SEIZMIK 10.5), Pekin Tuner, Townsend Supertweeters, Blue Jeans Digital,Kimber Speaker Chord Interconnect cables Kitchen Boom, Outdoors: SB Radio, Harmony One remote for everything. Phil Leigh's Profile: http://forums.slimdevices.com/member.php?userid=85 View this thread: http://forums.slimdevices.com/showthread.php?t=82050 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] Stereophile Review II: What conclusion can be drawn from the Measurements?
Phil Leigh;578558 Wrote: A -90dB sine wave is just not there in normal music. I'd like to hear JA's justification of why he thinks this is meaningful? Just saw this question. If you are talking about the undithered tone at -90.31dBFS I show in all my DAC measurements, I use this signal, not because it will be typical of music, but because it is diagnostic for DAC problems. In 2s-complement PCM encoding as used on CD, the change in level from digital 0 to +1 LSB actually involves all bits in the 16-bit word changing value. By contrast, the change from 0 to -1 LSB involves just the LSB changing value. So you can immediately see from the symmetry of the waveform, and how well-defined the 3 voltage levels are, whether or not the DAC is sufficiently monotonic and the analog noisefloor is sufficiently low to allow those data to be correctly decoded. In other words, it's a thumbnail indicator of DAC quality. In general, the test is not as useful in these days of sigma-delta DACs as it was when all we had were multi-bit DACs. However, you still come across pathological designs that fail to reproduce this signal properly - see, for example, fig.8 in the Cary review in the September 2010 issue of Stereophile. John Atkinson Editor, Stereophile -- Stereoeditor Stereoeditor's Profile: http://forums.slimdevices.com/member.php?userid=40770 View this thread: http://forums.slimdevices.com/showthread.php?t=82050 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] Stereophile Review II: What conclusion can be drawn from the Measurements?
adamdea;579122 Wrote: 1.2 It seems that an analog sytem has limited resolution but not limited precision. ... whilst a digital recoding may have 16 bit resolution and 16 bit precision, analogue systems can have 13 bit resolution and unlimited precision. Excuse me for coming in a bit late but I wanted to comment on this. Resolution and precision are two sides of the same coin. Here's an analogy. Take a 12 ruler - what is the smallest sized object you can confidently measure the size of? That's the resolution of your 12 ruler. Now measure something that's about 6 long - what's the accuracy with which you can measure its exact length? That's the precision. Can you see that both are constrained by the physical characteristics of the ruler itself, and are fundamentally the same thing? If you use a micrometer instead, you'll be able to both measure smaller objects (better resolution) and more accurately the size of relatively large objects (better precision). We can liken the 12 ruler to 8 bit digital audio and the micrometer to 16 bit audio. When it comes to audio, both resolution and precision are limited by the same thing: bit-depth (digital) or noise floor (analogue). They are just different ways of inaccurately measuring the voltage of a music signal. In particular, analogue does not have unlimited precision, because although (unlike digital) the voltage it delivers can be any arbitrary value, the noise floor means that the actual voltage is only an approximation. If the voltage should be 1V, an anlogue system might deliver anywhere between 0.999V or 1.001V, and you have no way of knowing what it should really be. It's a bit like you using that 12 ruler to measure an object is exactly 6 long - due to its lack of precision you are only in a position to say that it's somewhere between 5.95 and 6.05 -- cliveb Transporter - ATC SCM100A cliveb's Profile: http://forums.slimdevices.com/member.php?userid=348 View this thread: http://forums.slimdevices.com/showthread.php?t=82050 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] Stereophile Review II: What conclusion can be drawn from the Measurements?
cliveb;579311 Wrote: Excuse me for coming in a bit late but I wanted to comment on this. Resolution and precision are two sides of the same coin. Here's an analogy. Take a 12 ruler - what is the smallest sized object you can confidently measure the size of? That's the resolution of your 12 ruler. Now measure something that's about 6 long - what's the accuracy with which you can measure its exact length? That's the precision. Can you see that both are constrained by the physical characteristics of the ruler itself, and are fundamentally the same thing? If you use a micrometer instead, you'll be able to both measure smaller objects (better resolution) and more accurately the size of relatively large objects (better precision). We can liken the 12 ruler to 8 bit digital audio and the micrometer to 16 bit audio. When it comes to audio, both resolution and precision are limited by the same thing: bit-depth (digital) or noise floor (analogue). They are just different ways of inaccurately measuring the voltage of a music signal. In particular, analogue does not have unlimited precision, because although (unlike digital) the voltage it delivers can be any arbitrary value, the noise floor means that the actual voltage is only an approximation. If the voltage should be 1V, an anlogue system might deliver anywhere between 0.999V or 1.001V, and you have no way of knowing what it should really be. It's a bit like you using that 12 ruler to measure an object is exactly 6 long - due to its lack of precision you are only in a position to say that it's somewhere between 5.95 and 6.05 Thanks Clive - I can take the night off :-) -- Phil Leigh You want to see the signal path BEFORE it gets onto a CD/vinyl...it ain't what you'd call minimal... Touch(wired/XP) - TACT 2.2X (Linear PSU) + Good Vibrations S/W - MF Triplethreat(Audiocom full mods) - Linn 5103 - Aktiv 5.1 system (6x LK140's, ESPEK/TRIKAN/KATAN/SEIZMIK 10.5), Pekin Tuner, Townsend Supertweeters, Blue Jeans Digital,Kimber Speaker Chord Interconnect cables Kitchen Boom, Outdoors: SB Radio, Harmony One remote for everything. Phil Leigh's Profile: http://forums.slimdevices.com/member.php?userid=85 View this thread: http://forums.slimdevices.com/showthread.php?t=82050 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] Stereophile Review II: What conclusion can be drawn from the Measurements?
Phil Leigh;579158 Wrote: OK - bear in mind what I said before, the mid-point is 7 (not 8, my mistake). silence = 7 = 0111 In the UK, BBC FM radio in the late 60's through the 70's actually used a 13-bit digital system to relay the signal between transmitters. The sound quality in peoples homes was judged to be superb, despite the 13-bit digital link. Precision and resolution are two ways of looking at the same thing. More bits = greater precision (less quanitization error) and greater resolution (better SNR and DR). Resolution in this context simply means the range between the loudest sound and the quietest sound that can be captured. The number of bits determines this. Anyway, analogue systems do not have infinite anything. That is a myth. They clearly have limited resolution (SNR and DR). We could debate the term precision in an analogue context. Information theory tells us what is required to accurately sample an analogue signal. Correct. In an ADC. QN does not affect DAC's directly. What is meant by resolution here is really confusing. A 24-bit DAC (all 24-bit DAC's) can only really reproduce 21-bits of analogue signal AT BEST because the bottom 3 bits of both the ADC and DAC are measuring signals that are so tiny they are buried by thermal component noise (nothing to do with QN!). The digital part of the DAC has 24-bit resolution. The analogue side of the DAC has a resolution defined by the quietest sound you can hear that is not noise. This has almost nothing to do with the digital side and is largely governed by the componentry and circuit design of the analogue side of the ADC+DAC - including the power supply arrangements. Better, more expensive ADC+DAC's have less noise and can resolve up to 21-bits. What does this mean in practice? 1) Lots of tests indicate that no-one can hear anything beyond the 19th bit in normal circumstances... remember that even the 16th bit is incredibly low level... (-96dB) 2) This has no bearing whatsoever on anything other than what is the quietest non-noise signal that can be reproduced? 3) The DAC in the Touch is good but can be outperformed by external DAC's This is really helpful and clear. I follow all of this until we get to point number 2. I have been wondering how I could get to whether I understand what you mean by this. If we had recorded in 21 bit samples rather than 17 bit samples we would reduce quntisation noise at all levels- the quantisation error in your 4 bit example does not occur at the lowest volume level. The limited precision of the DAC will produce a greater error than with a higher precision DAC at all amplitude levels (although the error will be lower relative to that amplitude at higher levls than it is at lower levels). I see that the DAC can't itself produce quantisation noise becasue it doesn't quantise. But I keep thinking that this will be the case with a 24 bit dac with 21 bit or 17 bit resolution too ie that if their outputs were compared there would be an equivalent effect as though that error were being made in the ADC (albeit with dither) The DAC surely only has the same number of meaningful outputs as if the ADC had had 21 bit or 17 bit precision? I am trying to get my mind round how the limited resolution at the DAC output compares with a limited adc bit depth which is then converted into a 24 bit word (as I understand happens when redbook cds information is sent to a 24 bit DAC.) Presumably the 16 bit word has 8 arbitrary digits placed after it. Isn't the output of the DAC with 16 bit resolution feed 24 bit precision data going to be indistinguishable from the output of a 24 bit dac fed that upconverted data. Perhaps this could be illustrated by comparing 1 (imaginary) ADC with 24 bit resolution and the 24 bit dac DAC with 21 bit resolution 2 same ADC but DAC has only 20 bit resolution 3 now ADC also has only 20 bit resolution and DAC has 20 bit resolution. 4 now ADC is 17 bit but result is upconverted to 24 bit and played through 24 bit DAC with 20 bit resolution.. -- adamdea adamdea's Profile: http://forums.slimdevices.com/member.php?userid=37603 View this thread: http://forums.slimdevices.com/showthread.php?t=82050 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] Stereophile Review II: What conclusion can be drawn from the Measurements?
adamdea;579176 Wrote: This is really helpful and clear. I follow all of this until we get to point number 2. I have been wondering how I could get to whether I understand what you mean by this. If we had recorded in 21 bit samples rather than 17 bit samples we would reduce quntisation noise at all levels- the quantisation error in your 4 bit example does not occur at the lowest volume level. The limited precision of the DAC will produce a greater error than with a higher precision DAC at all amplitude levels (although the error will be lower relative to that amplitude at higher levls than it is at lower levels). I see that the DAC can't itself produce quantisation noise becasue it doesn't quantise. But I keep thinking that an equivalent effect will apply with a 24 bit dac with 21 bit or 17 bit resolution too ie that if their outputs were compared there would be an equivalent effect as though the ADC had limited precision (albeit with dither) The DAC surely only has the same number of meaningful outputs as if the ADC had had 21 bit or 17 bit precision? I am trying to get my mind round how the limited resolution at the DAC output compares with a limited adc bit depth which is then converted into a 24 bit word (as I understand happens when redbook cds' data is sent to a 24 bit DAC.) Presumably the 16 bit word has 8 arbitrary digits placed after it. Isn't the output of the DAC with 16 bit resolution fed 24 bit precision data going to be indistinguishable from the output of a 24 bit dac fed that upconverted data. Perhaps this could be illustrated by comparing 1 (imaginary) ADC with 24 bit resolution and the 24 bit dac DAC with 21 bit resolution 2 same ADC but DAC has only 20 bit resolution 3 now ADC also has only 20 bit resolution and DAC has 20 bit resolution. 4 now ADC is 17 bit but result is upconverted to 24 bit and played through 24 bit DAC with 20 bit resolution.. OK - I'll try. 1) Quantization error ALWAYS ONLY occurs in the lowest level - it is an error in the lowest bit - actually strictly speaking it's in the lowest half-bit(!) because 50% of the time the value chosen is correct... Let me put it another way. It doesn't matter what the sample value is, the error can only be +/- 1 bit. So the error in 12 vs 12.5 vs 13 is identical to the error in 1 vs 1.5. vs 2... You really need to be happy you understand this - as it is fundamental. 2) There's no concept of LIMITED PRECISION in a DAC. It has a precision, defined by how many bits it can handle. Period. You can argue its analogue side has a resolution defined as how high the noise floor is. 3) When redbook (16-bit) is converted to 24-bit, 8 bits of silence are added. Not 8 random bits. 4) in your 4 examples: 1: a true 24-bit ADC ( that doesn't exist) records music using all 24 bits. A 24-bit DAC will faithfully TRY and replay that. However if its analogue noise floor is effectively equivalent to 3 bits, you won't be able to hear anything but noise if you try and play a signal that only requires 3 bits or less of level. 2: exactly as per 1, except now signals using less than 4 bits are just noise 3: 4 bits of noise are recorded along with the music. A different 4 bits of noise appear at the analogue output of the DAC 4: The music is in the 17 bits (I'm assuming you are talking about an imaginary ADC with only 17 bits?). Converting this to 24-bit puts silence into the lowest 7 bits. Played back you hear 17 bits of music. Conclusions: 1) Stop reading Stereophile, it is just confusing you 2) If all of this still bothers you, just use an external DAC. You may not hear much difference. -- Phil Leigh You want to see the signal path BEFORE it gets onto a CD/vinyl...it ain't what you'd call minimal... Touch(wired/XP) - TACT 2.2X (Linear PSU) + Good Vibrations S/W - MF Triplethreat(Audiocom full mods) - Linn 5103 - Aktiv 5.1 system (6x LK140's, ESPEK/TRIKAN/KATAN/SEIZMIK 10.5), Pekin Tuner, Townsend Supertweeters, Blue Jeans Digital,Kimber Speaker Chord Interconnect cables Kitchen Boom, Outdoors: SB Radio, Harmony One remote for everything. Phil Leigh's Profile: http://forums.slimdevices.com/member.php?userid=85 View this thread: http://forums.slimdevices.com/showthread.php?t=82050 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] Stereophile Review II: What conclusion can be drawn from the Measurements?
Thanks. Got back from the Opera. Read this. Thought I understood it, but thought it best to go to bed and re-read in the morning. -- adamdea adamdea's Profile: http://forums.slimdevices.com/member.php?userid=37603 View this thread: http://forums.slimdevices.com/showthread.php?t=82050 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] Stereophile Review II: What conclusion can be drawn from the Measurements?
adamdea;578884 Wrote: ... I see that as the sound gets louder the difference between peak and trough gets wider. I think I understand the illustration about precision. Is it correct that the error you refer to as a result of fixed precision is the same as quantisation noise? (ducks). Yes this is Quantization Error/Quantization Noise and is what happens in an ADC - which is really what we are describing in these examples. A DAC doesn't have this issue because it only plays back EXACTLY the samples given to it - it doesn't have to make tough choices about intermediate values, like an ADC does. The Quantization Error in an ADC is what is addressed by either: 1) adding dither or noise shaping to randomize these erorrs so you can't hear the granularity in very low level signals 2) recording with more bits so the errors are far fewer and lower in level. adamdea;578884 Wrote: ... If you reduced by 24 db would you get 8 8 8 9 8 8 8 8 8 7 8 8 8. (I said 24 db because you said it was a 6 db reduction in your example but I confess I don't understand the 6 db equivalence. I just mean getting quieter to the point where the peak becomes 9 and the trough 7) ..and below that level it would just be 8s? This is a 4-bit example. Each bit value is double the previous bit (8-4-2-1 ... binary math). Doubling in audio = approx 6dB. with 4 bits you can only capture a total of 24dB of dynamic range... So if you reduced the level by 24dB you would have nothing! (silence) Remember the smallest amount you can reduce by is 1 bit... so you just keep taking one bit off both the top and bottom values until you are left with all 8's. So in the 4-bit example, you can reduce a full scale (15-0) wave 7 times/steps until both 15 and 0 become 8. (actually I've just realised in all my examples it is 7 that is the zero-crossing point, not 8 - doh! schoolboy error, I must learn to count). adamdea;578884 Wrote: ... Is the point at which it becomes all 8s the resolution of the system (or is perhaps the other way round- is the point at which a signal stops being all 8s the resolution?) Is there a way of illustrating noise (other than quantisation noise) in this example Resolution is number of bits used to capture the signal. It defines the number of different steps in level available from max to min. 4-bit = 16 possible values but remember these come in pairs around the crossing point so really its 8 steps including silence... This in turn defines the QUIETEST sound that can be captured (1 bit above silence) relative to the loudest sound that can be captured. This is the dynamic range! So if you were recording a 100dB real world signal and 100dB was going to be full-scale (15-0), the quietest sound you could capture at the same time would be 76dB. This is why we don't use 4 bits... :-) Recap: the smallest variation in signal that can be captured is 1 bit. The effective audible resolution depends on the number of bits in total, as that defines the difference in level between the loudest and quietest sounds and therefore what each bit is worth... Noise (other than QN) is produced in the analogue circuitry of the ADC/DAC. It is very low level. It has nothing to do with bit-depth per se. The reason why 24 bit ADC's and DACS are really 21-bit in practice is that the noise (which is a constant and comes from the thermal or Johnson noise in resistors etc) is greater than the level that can be captured/generated by the sum of the lowest 3 bits. The noise is a constant, but if you record AN ENTIRE TRACK at low level you will have to turn up your amp to hear it... and the noise gets louder too. At a very low level of recording, you will eventually lose the signal in the noise floor... In the 4-bit example, the noise floor is only 24dB away from the loudest signal!. I think perhaps you are trying to look for something that just isn't there? There is no fundamental flaw in the digital process that has not been addressed one way or another. The biggest danger is using too few bits or recording things at too low a level in the first place, such that the signal is too close to the noise floor. 24-bit helps both of those and in practice 16-bit is good enough in many circumstances. The use of 24-bit recording also reduces the need for dithering or noise shaping, since the bottom 3 bits effectively provide that random noise element anyway... adamdea;578884 Wrote: ... I am also wondering what happens when the 4 bit DA converter now only has 3 bit resolution Remember we are talking about ADC, not DAC. A 3-bit ADC would be exactly the same as the 4-bit one except that its max dynamic range would be 18dB. adamdea;578884 Wrote: ... In the example you give the crossing point is midway between the highest and lowest possible values which can be expressed. As you increase loudness it would max out at the same time it mins out. Can you have different triangular waves with the same difference
Re: [SlimDevices: Audiophiles] Stereophile Review II: What conclusion can be drawn from the Measurements?
Quote: Originally Posted by adamdea ... If you reduced by 24 db would you get 8 8 8 9 8 8 8 8 8 7 8 8 8. (I said 24 db because you said it was a 6 db reduction in your example but I confess I don't understand the 6 db equivalence. I just mean getting quieter to the point where the peak becomes 9 and the trough 7) ..and below that level it would just be 8s? This is a 4-bit example. Each bit value is double the previous bit (8-4-2-1 ... binary math). Doubling in audio = approx 6dB. with 4 bits you can only capture a total of 24dB of dynamic range... So if you reduced the level by 24dB you would have nothing! (silence) Remember the smallest amount you can reduce by is 1 bit... so you just keep taking one bit off both the top and bottom values until you are left with all 8's. So in the 4-bit example, you can reduce a full scale (15-0) wave 7 times/steps until both 15 and 0 become 8. (actually I've just realised in all my examples it is 7 that is the zero-crossing point, not 8 - doh! schoolboy error, I must learn to count). unquote You can feel free to ignore the bit in brackets. If it is annoying just move on. [I understand the 6 dB = 1 bit equivalence. But in your example when you reduced the peak and raised by trough by 1 from 14 to 13 you described it as a 6db reduction. (I assumed from that that each iteration represented 6db). I wonder whether the reduction by 1 should have been a 3 dB reduction. I was simply reducing the peak etc by 4 more stages in the example I gave. There seem to be 7 reductions before your signal becomes 7s and 8s. I cant see any way of reducing the a 15, 0 starting pair to get either 8 or 7- I wonder whether this is because the crossing point is the same as the median value (7.5). If so I am now baffled as to how one expresses silence in this 4 bit word.(pehaps you ignore 0, leaving 15 values and a happy median of 8).] Now what was the point? Well I was tryign to work out whether we could clarify the previous discussion by actually drilling down to the numbers. I think that it is very difficult to discuss technical (especially mathematical relationships in everyday english. I have noticed for example that on the news they often trip up when tryign to discuss economic (or econometric) concepts like say the distinction between the stock of public debt, the budget deficit, a change in the budget deficit. As to where this takes us 1.1 You have pointed out that in information theory terms i have been confusing two terms precision and resolution. These seem to correspond with 2 problems a. the quantisation noise cuased by the limited choice of sample values b. the inabilty to produce a sound quieter than the lowest value (apparently over or above the crossing value.) 1.2 It seems that an analog sytem has limited resolution but not limited precision. If we return to your post 33, you described radio 3 as 13 bit. I assume that you meant that it had a snr of 78 dB. I have been making the point at various stages (although apparently without using the correct terminology) that whilst a digital recoding may have 16 bit resolution and 16 bit precision, analogue systems can have 13 bit resolution and unlimited precision. OR have I got this wrong and was the 13 bit radio limited in both resoltuion and precision? 1.3 I am assuming that if a sound gets quieter it not only gets closer to the noise floor but the quantisation noise relative to signal increases. II. My major concern was over the example of the 24 bit DAC which has only 17 bit resolution. I think this means it can only resolve a sound 102dB below peak. I am however confused as to what this means about its precision. I understand that the DAC doesn't have to guess at the values it is decoding, but isn't the output the same as if it were reading a 17 bit recording with 7 random numbers on the end . Does this not mean that not only does the noise floor increase but the quantisation noise will increase? -- adamdea adamdea's Profile: http://forums.slimdevices.com/member.php?userid=37603 View this thread: http://forums.slimdevices.com/showthread.php?t=82050 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] Stereophile Review II: What conclusion can be drawn from the Measurements?
adamdea;579122 Wrote: Quote: Originally Posted by adamdea ... ... There seem to be 7 reductions before your signal becomes 7s and 8s. I cant see any way of reducing the a 15, 0 starting pair to get either 8 or 7- I wonder whether this is because the crossing point is the same as the median value (7.5). If so I am now baffled as to how one expresses silence in this 4 bit word.(pehaps you ignore 0, leaving 15 values and a happy median of 8).] . OK - bear in mind what I said before, the mid-point is 7 (not 8, my mistake). silence = 7 = 0111 adamdea;579122 Wrote: ...As to where this takes us 1.1 You have pointed out that in information theory terms i have been confusing two terms precision and resolution. These seem to correspond with 2 problems a. the quantisation noise cuased by the limited choice of sample values b. the inabilty to produce a sound quieter than the lowest value (apparently over or above the crossing value.) 1.2 It seems that an analog sytem has limited resolution but not limited precision. If we return to your post 33, you described radio 3 as 13 bit. I assume that you meant that it had a snr of 78 dB. I have been making the point at various stages (although apparently without using the correct terminology) that whilst a digital recoding may have 16 bit resolution and 16 bit precision, analogue systems can have 13 bit resolution and unlimited precision. OR have I got this wrong and was the 13 bit radio limited in both resoltuion and precision? . In the UK, BBC FM radio in the late 60's through the 70's actually used a 13-bit digital system to relay the signal between transmitters. The sound quality in peoples homes was judged to be superb, despite the 13-bit digital link. Precision and resolution are two ways of looking at the same thing. More bits = greater precision (less quanitization error) and greater resolution (better SNR and DR). Resolution in this context simply means the range between the loudest sound and the quietest sound that can be captured. The number of bits determines this. Anyway, analogue systems do not have infinite anything. That is a myth. They clearly have limited resolution (SNR and DR). We could debate the term precision in an analogue context. Information theory tells us what is required to accurately sample an analogue signal. adamdea;579122 Wrote: 1.3 I am assuming that if a sound gets quieter it not only gets closer to the noise floor but the quantisation noise relative to signal increases. . Correct. In an ADC. QN does not affect DAC's directly. adamdea;579122 Wrote: II. My major concern was over the example of the 24 bit DAC which has only 17 bit resolution. I think this means it can only resolve a sound 102dB below peak. I am however confused as to what this means about its precision. I understand that the DAC doesn't have to guess at the values it is decoding, but isn't the output the same as if it were reading a 17 bit recording with 7 random numbers on the end . Does this not mean that not only does the noise floor increase but the quantisation noise will increase (or a noise equal to the level of quantisation noise which would have appeared if the recording had been at 17 bits?) Anyway thank you for your patience. What is meant by resolution here is really confusing. A 24-bit DAC (all 24-bit DAC's) can only really reproduce 21-bits of analogue signal AT BEST because the bottom 3 bits of both the ADC and DAC are measuring signals that are so tiny they are buried by thermal component noise (nothing to do with QN!). The digital part of the DAC has 24-bit resolution. The analogue side of the DAC has a resolution defined by the quietest sound you can hear that is not noise. This has almost nothing to do with the digital side and is largely governed by the componentry and circuit design of the analogue side of the ADC+DAC - including the power supply arrangements. Better, more expensive ADC+DAC's have less noise and can resolve up to 21-bits. What does this mean in practice? 1) Lots of tests indicate that no-one can hear anything beyond the 19th bit in normal circumstances... remember that even the 16th bit is incredibly low level... (-96dB) 2) This has no bearing whatsoever on anything other than what is the quietest non-noise signal that can be reproduced? 3) The DAC in the Touch is good but can be outperformed by external DAC's -- Phil Leigh You want to see the signal path BEFORE it gets onto a CD/vinyl...it ain't what you'd call minimal... Touch(wired/XP) - TACT 2.2X (Linear PSU) + Good Vibrations S/W - MF Triplethreat(Audiocom full mods) - Linn 5103 - Aktiv 5.1 system (6x LK140's, ESPEK/TRIKAN/KATAN/SEIZMIK 10.5), Pekin Tuner, Townsend Supertweeters, Blue Jeans Digital,Kimber Speaker Chord Interconnect cables Kitchen Boom, Outdoors: SB Radio, Harmony One remote for everything. Phil Leigh's
Re: [SlimDevices: Audiophiles] Stereophile Review II: What conclusion can be drawn from the Measurements?
adamdea;578793 Wrote: I have been studying this quite carefully as there are lots of useful points. I promise it wasn't point 1 I was missing and I don't think it was point 3 although I guess I do find the terms resolution and precision confusing. (I have been puzzling over the question of what the precision of an analogue system is) I also undertake never to allow my mind to wander into visual analogies. What I am getting confused about is what happens when a sound (which, obviously as you point out, has an amplitude that varies over time)gets louder and softer. Let's assume there is no other sound in the recording. If the sound (is it allowed to be a sine wave?) varies in amplitude between 128 and 32- xxx...1000 and 0010 and it became louder so that the peak amplitude was 2048 xxx1000, what would be the number which now represents the minimum amplitude of this wave? Would it be 1952 (010 ?) or something else? I have a feeling that if I could grasp this I could understand the point. I'm sorry, and don't take this bad. I don't want you recording me if I become famous. It won't happen unless I die in an outstanding way but still. -- Nonreality -IF THE RULE YOU FOLLOWED BROUGHT YOU TO THIS, OF WHAT USE IS THE RULE.- HTTP://www.last.fm/user/nonreality Nonreality's Profile: http://forums.slimdevices.com/member.php?userid=15723 View this thread: http://forums.slimdevices.com/showthread.php?t=82050 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] Stereophile Review II: What conclusion can be drawn from the Measurements?
adamdea;578793 Wrote: I have been studying this quite carefully as there are lots of useful points. I promise it wasn't point 1 I was missing and I don't think it was point 3 although I guess I do find the terms resolution and precision confusing. (I have been puzzling over the question of what the precision of an analogue system is) I also undertake never to allow my mind to wander into visual analogies. What I am getting confused about is what happens when a sound (which, obviously as you point out, has an amplitude that varies over time)gets louder and softer. Let's assume there is no other sound in the recording. If the sound (is it allowed to be a sine wave?) varies in amplitude between 128 and 32- xxx...1000 and 0010 and it became louder so that the peak amplitude was 2048 xxx1000, what would be the number which now represents the minimum amplitude of this wave? Would it be 1952 (010 ?) or something else? I have a feeling that if I could grasp this I could understand the point. OK - I'll try, but only if you promise to stop with the photography analogies :-) 1) all sound can be represented by the summation of a series of sine wives (Fourier) - so yes, the simplest sound is a pure sine wave. However, lets use a triangle wave instead to keep the maths simpler 2) To keep it simple, lets use 4 bits instead of 16 so the max decimal value is 15 and the min is 0, with the zero-crossing point being 8 (8 = silence) 3) so, a fixed frequency triangle wave (say 1kHz) sampled at a sampling frequency of 13kHz (so you get 13 samples per wavelength) could be: 8 10 12 14 12 10 8 6 4 2 4 6 8 That would be very loud. if we reduced the level by 6dB we'd get: 8 9 11 13 11 9 8 7 5 3 5 7 8 You can see that the level (wave amplitude) has been reduced by 1 bit at each sampling point except at the zero crossing point of the waveform (you can't have less than zero). But look - we started with 8 10 12 14, now we have 8 9 11 13 - our nice triangle slope is distorted! we wanted to go 8 9.5 11 12.5 - but we can't!!! This neatly illustrates the problem with recording in 4-bits!... you get the idea - now we have insufficient precision to record the correct value so we have to choose... Whatever we choose will be wrong... More bits = bigger numbers = more precision in the sample values = smaller errors when we change the numbers later. in binary the two sequences would be: 8 10 12 14 12 10 8 6 4 2 4 6 8 8421 1000 1010 1100 1110 1100 1010 1000 0110 0100 0010 0100 0110 1000 changed to: 8 9 11 13 11 9 8 7 5 3 5 7 8 8421 1000 1001 1011 1101 1011 1001 1000 0111 0101 0011 0101 0111 1000 Does this help? Maybe it's the zero-crossing issue that's throwing you? I've used 4 bits here to exaggerate the issue. As you increase the number of bits available, the rounding error problem diminishes - you get increasingly precise numbers at each sample point... and if you perform any kind of DSP - which always involves floating point maths - on fixed precision numbers you get errors. More bits=smaller errors. OK - I'll let you have a photo analogy now :-) bits in audio (representation of amplitude) are similar to bits in photography (representation of contrast/hue). Less bits = less gradation of contrast and less pallete range. 1 bit = pure black white (or a full scale pure square wave in audio whose only variable is the mark/space ratio) -- Phil Leigh You want to see the signal path BEFORE it gets onto a CD/vinyl...it ain't what you'd call minimal... Touch(wired/XP) - TACT 2.2X (Linear PSU) + Good Vibrations S/W - MF Triplethreat(Audiocom full mods) - Linn 5103 - Aktiv 5.1 system (6x LK140's, ESPEK/TRIKAN/KATAN/SEIZMIK 10.5), Pekin Tuner, Townsend Supertweeters, Blue Jeans Digital,Kimber Speaker Chord Interconnect cables Kitchen Boom, Outdoors: SB Radio, Harmony One remote for everything. Phil Leigh's Profile: http://forums.slimdevices.com/member.php?userid=85 View this thread: http://forums.slimdevices.com/showthread.php?t=82050 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] Stereophile Review II: What conclusion can be drawn from the Measurements?
Phil Leigh;578811 Wrote: OK - I'll try, but only if you promise to stop with the photography analogies :-) 1) all sound can be represented by the summation of a series of sine wives (Fourier) - so yes, the simplest sound is a pure sine wave. However, lets use a triangle wave instead to keep the maths simpler 2) To keep it simple, lets use 4 bits instead of 16 so the max decimal value is 15 and the min is 0, with the zero-crossing point being 8 (8 = silence) 3) so, a fixed frequency triangle wave (say 1kHz) sampled at a sampling frequency of 13kHz (so you get 13 samples per wavelength) could be: 8 10 12 14 12 10 8 6 4 2 4 6 8 That would be very loud. if we reduced the level by 6dB we'd get: 8 9 11 13 11 9 8 7 5 3 5 7 8 You can see that the level (wave amplitude) has been reduced by 1 bit at each sampling point except at the zero crossing point of the waveform (you can't have less than zero). But look - we started with 8 10 12 14, now we have 8 9 11 13 - our nice triangle slope is distorted! we wanted to go 8 9.5 11 12.5 - but we can't!!! This neatly illustrates the problem with recording in 4-bits!... you get the idea - now we have insufficient precision to record the correct value so we have to choose... Whatever we choose will be wrong... More bits = bigger numbers = more precision in the sample values = smaller errors when capture them AND if we change the numbers later. in binary the two sequences would be: 8 10 12 14 12 10 8 6 4 2 4 6 8 8421 1000 1010 1100 1110 1100 1010 1000 0110 0100 0010 0100 0110 1000 changed to: 8 9 11 13 11 9 8 7 5 3 5 7 8 8421 1000 1001 1011 1101 1011 1001 1000 0111 0101 0011 0101 0111 1000 Does this help? Maybe it's the zero-crossing issue that's throwing you? I've used 4 bits here to exaggerate the issue. As you increase the number of bits available, the rounding error problem diminishes - you get increasingly precise numbers at each sample point... and if you perform any kind of DSP - which always involves floating point maths - on fixed precision numbers you get errors. More bits=smaller errors. OK - I'll let you have a photo analogy now :-) bits in audio (representation of amplitude) are similar to bits in photography (representation of contrast/hue). Less bits = less gradation of contrast and less pallete range. 1 bit = pure black white (or a full scale pure square wave in audio whose only variable is the mark/space ratio) Do you realize what you might have started? Such a bad/good person. Time will tell. -- Nonreality -IF THE RULE YOU FOLLOWED BROUGHT YOU TO THIS, OF WHAT USE IS THE RULE.- HTTP://www.last.fm/user/nonreality Nonreality's Profile: http://forums.slimdevices.com/member.php?userid=15723 View this thread: http://forums.slimdevices.com/showthread.php?t=82050 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] Stereophile Review II: What conclusion can be drawn from the Measurements?
Nonreality;578812 Wrote: Do you realize what you might have started? Such a bad/good person. Time will tell. Nonreality - You may be right. I was a bit apprehensive when I posted this... -- Phil Leigh You want to see the signal path BEFORE it gets onto a CD/vinyl...it ain't what you'd call minimal... Touch(wired/XP) - TACT 2.2X (Linear PSU) + Good Vibrations S/W - MF Triplethreat(Audiocom full mods) - Linn 5103 - Aktiv 5.1 system (6x LK140's, ESPEK/TRIKAN/KATAN/SEIZMIK 10.5), Pekin Tuner, Townsend Supertweeters, Blue Jeans Digital,Kimber Speaker Chord Interconnect cables Kitchen Boom, Outdoors: SB Radio, Harmony One remote for everything. Phil Leigh's Profile: http://forums.slimdevices.com/member.php?userid=85 View this thread: http://forums.slimdevices.com/showthread.php?t=82050 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] Stereophile Review II: What conclusion can be drawn from the Measurements?
adamdea;578793 Wrote: If the sound (is it allowed to be a sine wave?) varies in amplitude between 128 and 32- xxx...1000 and 0010 and it became louder so that the peak amplitude was 2048 xxx1000, what would be the number which now represents the minimum amplitude of this wave? Would it be 1952 (010 ?) or something else? I don't know the answer to that, but it seems to me that your example has a DC bias. If we define origo (zero) to the middle then the signal would probably vary between 128 and -128, or 32 and -32. (Or if you define origo (zero) to be all bits=zero then 128 would be the middle (silence), and the signal would vary between 256 and 0, or 160 and 96.) Or perhaps I misunderstood you completely. :P -- Soulkeeper -that is not dead which can eternal lie. and with strange aeons even death may die.- duet + boom + radio (+touch on the way (or maybe not)) / wrt160n/dd-wrt / sbs 7.5.1 or higher/win7(32b)/avira free Soulkeeper's Profile: http://forums.slimdevices.com/member.php?userid=35297 View this thread: http://forums.slimdevices.com/showthread.php?t=82050 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] Stereophile Review II: What conclusion can be drawn from the Measurements?
Yes this is very helpful. Thanks: I guess it must have taken a while, even if it is child's play to you. I think it might be the crossing point that I didn't get (I mean I know there is one in a sine wave but not how this translates into sampled amplitude.) I am really interested in trying to understand how this works and relates back to the concepts discussed previously. This means unfortunately that I have lots of questions and that they are probably dumb. I see that as the sound gets louder the difference between peak and trough gets wider. I think I understand the illustration about precision. Is it correct that the error you refer to as a result of fixed precision is the same as quantisation noise? (ducks). If you reduced by 24 db would you get 8 8 8 9 8 8 8 8 8 7 8 8 8. (I said 24 db because you said it was a 6 db reduction in your example but I confess I don't understand the 6 db equivalence. I just mean getting quieter to the point where the peak becomes 9 and the trough 7) ..and below that level it would just be 8s? Is the point at which it becomes all 8s the resolution of the system (or is perhaps the other way round- is the point at which a signal stops being all 8s the resolution?) Is there a way of illustrating noise (other than quantisation noise) in this example I am also wondering what happens when the 4 bit DA converter now only has 3 bit resolution In the example you give the crossing point is midway between the highest and lowest possible values which can be expressed. As you increase loudness it would max out at the same time it mins out. Can you have different triangular waves with the same difference between peak and trough, but with a different crossing point? (obviously you can mathematically, but I am wondering whether this corresponds to a possible sound wave). -- adamdea adamdea's Profile: http://forums.slimdevices.com/member.php?userid=37603 View this thread: http://forums.slimdevices.com/showthread.php?t=82050 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] Stereophile Review II: What conclusion can be drawn from the Measurements?
Nonreality;578807 Wrote: I'm sorry, and don't take this bad. I don't want you recording me if I become famous. It won't happen unless I die in an outstanding way but still. I don't take it badly. Not least because if you become famous having died in an outstanding way it will be too late then. -- adamdea adamdea's Profile: http://forums.slimdevices.com/member.php?userid=37603 View this thread: http://forums.slimdevices.com/showthread.php?t=82050 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] Stereophile Review II: What conclusion can be drawn from the Measurements?
Phil Leigh;578522 Wrote:
OH - and I thought you were about to understand! :-)
1) all 16/24 bits represent the quiet sound, same as they do a loud
sound. The fact that several of them are zero makes no difference
except to the SNR. You have to stop thinking about bits as things in
their own right. They aren't - they are just part of a word that
represents the level (loudness) of something when you add ALL of the
bits together.
2) You also have to leave behind the digital photography analogies
because they aren't helping you to understand at all. In photography
each pixel is equivalent to a sample and has a bit-depth. BUT and it is
a MASSIVE But... when you look at a digital image you see all the
samples at once fixed in time, whereas in audio the sound is produced
by a variation in amplitude over time - that's all sound is! So in
audio, it is the change over time that matters. This is why pictures
get blocky when you zoom in - eventually you can see individual
samples - which make no visual sense in isolation.
There is NO equivalent to this in audio - without special tools (DSP)
you can't alter the timeframe in which you hear the sounds - and the
sounds themselves change (in pitch and duration) if you try. You can't
hear a single audio sample - in isolation it has no sound. You can
see a pixel.
3) I don't think you've grasped the meaning of precision vs resolution
yet. In your 7-bit example, there are NOT only 7-bits worth of values
to represent the sound... 7-bits is just what it takes to represent the
LOUDNESS of THAT sound. The fact that the higher bits have zeroes in
them doesn't mean anything for the quality of the sound other than it
is quiet so you have more chance of hearing the noise floor intrude
into it.
If the quiet sound was made louder it would be captured with the same
precision, but a greater SNR.
{upper case for emphasis]
IN LINEAR PCM, RESOLUTION IS A FIXED PRODUCT OF BIT-DEPTH. It does not
vary with volume.
In lossy compression (MP3 et al) bit-depth...and thus
resolution...varies.
4) Your optical vs digital zoom analogy is not provocative - merely
wrong :-)
Analogue sources do NOT have infinite resolution. Nor do our ears, in
fact - but that's way OT.
Tape is limited by several things, including the tape speed, tape
width, tape head gap and magnetic particle size, all of which culminate
in a finite resolution. Likewise, vinyl is ultimately limited by the
physics of both the cutter head, the replay stylus, the pressing
process and the material properties of the final vinyl - all of which
limit the accurate recording of tiny (quiet) details.
I'll casually ignore the fact that most vinyl is cut from digital
masters in the last 20+ years... :-)
Replaying quiet sounds is NOT the same as recording with less bits!
Try the SB volume control - as you wind the volume all the way down the
sound doesn't get nasty grittier like a pixellating image - it gets:
1) quieter
2) noisier
3) eventually some of the quietest parts will no longer be audible...
just like they would with any analogue source... this is simply because
they are too quiet to be heard, both in relation to the noise floor and
to the loudest parts.
I have been studying this quite carefully as there are lots of useful
points. I promise it wasn't point 1 I was missing and I don't think it
was point 3 although I guess I do find the terms resolution and
precision confusing. (I have been puzzling over the question of what
the precision of an analogue system is)
I also undertake never to allow my mind to wander into visual
analogies.
What I am getting confused about is what happens when a sound (which,
obviously as you point out, has an amplitude that varies over time)gets
louder and softer. Let's assume there is no other sound in the
recording. If the sound (is it allowed to be a sine wave?) varies in
amplitude between 128 and 32- xxx...1000 and 0010
and it became louder so that the peak amplitude was 2048
xxx1000, what would be the number which now represents the
minimum amplitude of this wave? Would it be 1952 (010 ?) or
something else?
I have a feeling that if I could grasp this I could understand the
point.
--
adamdea
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Re: [SlimDevices: Audiophiles] Stereophile Review II: What conclusion can be drawn from the Measurements?
seanadams;578418 Wrote: Huh? If the levels are maxed into the ADC then you are getting all the dynamic range of the LP, and then some. If the source medium is in a quiet passage then whatever resolution you're talking about (relative to its peak amplitude in THAT little section) was already lost when it was pressed. It is simply gone, and boosting the level or using a higher res ADC isn't going to bring it back. Sure, the dynamic range is there. When it comes to resolution of vinyl records we probably disagree a bit. I believe a good LP has more information than RBCD. Not necessarily at high levels, but certainly down at -40 - -50 dB. I naturally agree with you that lost information will not be restored by using a higher resolution ADC -- OGS Vortexbox - Touch - Tact RCS 2.0 - Rotel RB-1060 (mod) - Tannoy Sensys DC1 (mod) OGS's Profile: http://forums.slimdevices.com/member.php?userid=32981 View this thread: http://forums.slimdevices.com/showthread.php?t=82050 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] Stereophile Review II: What conclusion can be drawn from the Measurements?
Phil Leigh;578308 Wrote: No - rgh - start again :-) Your TV analogy doesn't apply at all. Twice the pixel density = four times the file fize = 4x information. Bit depth increase from 16 to 24 = file size goes up by 50% because each number (sample) being stored is +50% more precise. The number of possible values only affects the PRECISION of each sample. It doesn't alter the amount of information, just its accuracy. The only way in which all bits are equal is that each bit gives you 6dB of Dynamic Range. When there loud stuff going on you simply can't hear the loss of the really quiet stuff. On classical music with protracted passages at -30dB... you might. The other place to look is in the reverb tails at the very end of tracks. Of course it's much MUCH easier for us to hear loud things... and very hard for us to hear quiet things happening at the same time as loud things. This is part of the reason why MP3 compression works at all. It also explains why 13-bit radio was considered state of the art (better than any available tape machine!) in the 70's and why some fairly serious test have shown that you have to reduce bit-depth to about 10 before MOST people hear a definite degradation in sound quality. ...and why Philips thought 14-bit DACs on early CD players were a good idea... 10 bits would equate to 60dB SNR which is not great - but it's about on par with good non-Dolby cassette playback... So no, the difference between 16 and 24 (21) bit playback is not huge by any way you want to measure it. The real benefits of 24-bit are: 1) greater headroom and more accurate DSP in recording / mastering = less distortion/noise - and these benefits are mostly retained after dithering down to 16-bit - if done properly. 2) the most non-linear bits are the lowest ones and they are further away from audible music in 24-bit DAC's than in 16-bit DAC's 3) A theroretically lower absolute noise floor, but as I've explained, in practice this compromised to some extent by the ADC's and other upstream equipment inthe recording chain. Probably still worthwhile though Really it's item 1 that makes 24-bit very important. I'm sure you're right about the first part, and my attempted analogy was unwise, and i am very grateful for the correction. However it is correct that the 19 bit binary number has 8 times more possible values as i said. I can see that this is not really analagous to the number of pixels, and in information theory terms is not an increase in the amount of information only its precision. I still can't see how the increase in bit depths can only be relevant to the resolution of noise at low levels as opposed to the resolution of small differences at higher levels. The question I was addressing (however ineptly) was whether and if so why an increase in DAC resolution of 16 bits to 19 is significant (you can take huge or strictly in this case not huge to mean a variety of things in different contexts.) The benefit of 24 bit recording is not the issue although I can see that the issues are related because if there were no benefit in 24 bit recording vs 16 bit, there couldn't be any benefit in any more than 16 bit playback. I remain intrigued by the feeling that the the maximum signal relative to noise floor is not the issue, which is why many people feel that analogue signals with high noise floor can still have a greater resolution than even properly implemented 16 bit. *Perhaps you can help me on this, Sean: if an analog system has an snr of 14 bit equivalent, does this mean that its resolution of noises of amplitude above the noise floor at best equal to 14 bit?*. The comment in audiophile terms is one I would happily stand by as it is a very important qualifier. Audiophiles spend large amount on small incremental improvements. -- adamdea adamdea's Profile: http://forums.slimdevices.com/member.php?userid=37603 View this thread: http://forums.slimdevices.com/showthread.php?t=82050 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] Stereophile Review II: What conclusion can be drawn from the Measurements?
Phil Leigh;578434 Wrote: The resolution and maximum SNR/DR is a fixed property of the bit-depth. What changes on a sample-by-sample basis is the SNR depending on the sample value. So a quiet passage won't have less resolution - all 16/24 bits are still being used to represent it, but it will have a lower SNR. Just like an analogue tape recorder. I may have misunderstood how this works. I have no real experience with recording live music so I appreciate the information you present Phil. If you record an acoustic trio as loud as possible with no clipping in 24bit, in a hall with medium ambient noise, then when there is no playing the level meters register around (say) -50 dB. At what digital resolution is the ambient recorded? Then you store the recording in 16bit for transfer to CD (I know, noise shaping is used to improve quality if this was to be a real product). The level of the ambient noise is still -50dB so what is the digital resolution now? -- OGS Vortexbox - Touch - Tact RCS 2.0 - Rotel RB-1060 (mod) - Tannoy Sensys DC1 (mod) OGS's Profile: http://forums.slimdevices.com/member.php?userid=32981 View this thread: http://forums.slimdevices.com/showthread.php?t=82050 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] Stereophile Review II: What conclusion can be drawn from the Measurements?
Phil Leigh;578434 Wrote: The resolution and maximum SNR/DR is a fixed property of the bit-depth. What changes on a sample-by-sample basis is the SNR depending on the sample value. So a quiet passage won't have less resolution - all 16/24 bits are still being used to represent it, but it will have a lower SNR. Just like an analogue tape recorder. I think the point that was being made [and at this point I pause to stress that it is not my point but i am telling you what i think the point is] was that if you isolate the recording of a quiet sound maxing 7 bits above digital noise floor, then this would be the same as a 7 bit recording of this noise alone using the full dynamic range of the 7 bits. You may say that all 16/24 bits represent the quiet noise, but there are only 7 bits worth of possible values representing this quiet noise [I am not quite sure this is the case]. If the quiet noise had been make much louder then it would have had the benefit not only of being at a higher level but having been captured with greater precision. If you assumed that the analog sytem would be able to resove that lw level noise with infinite resolution (on the assumtion that nalog recording works like an optical zoom rather than a digital zoom [provocative or what]) then the analog recording of this sound would be better. -- adamdea adamdea's Profile: http://forums.slimdevices.com/member.php?userid=37603 View this thread: http://forums.slimdevices.com/showthread.php?t=82050 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] Stereophile Review II: What conclusion can be drawn from the Measurements?
adamdea;578475 Wrote: ... i think the point is] was that if you isolate the recording of a quiet sound maxing 7 bits above digital noise floor, then this would be the same as a 7 bit recording of this noise alone using the full dynamic range of the 7 bits. [snip] ...If you assumed that the analog sytem would be able to resove that low level noise with infinite resolution (on the assumption that analog recording works like an optical zoom rather than a digital zoom [provocative or what]) then the analog recording of this sound would be better. Having done a fair amount of analog recording with open reel over the years, I can assure you that if you have an open reel with 65 or even 70 dB of S/N, when you have a quiet passage 50 dB down, you're still in a spot where the recorded info still has only 15 or 20 dB of S/N to work with and the noise floor inserts itself into the music. That in itself represents a loss of resolution. Lost is this discussion is that quiet passages in music were meant by the composer and/or artist to be quiet. Therefore they are more subject to extraneous noise. It is meant that you have to strain or work to hear them versus turning up the volume and expecting them to sound identical to the loud passages. I find most of the defects in CD recordings were the result of intentional recording and mixing choices made by the artist, engineer or producer. I have any number of CDs that are absolutely wonderful in their dynamic range and presentation of quiet passages. If one CD can get that right, then it's not the format, and I have many. -- mlsstl mlsstl's Profile: http://forums.slimdevices.com/member.php?userid=9598 View this thread: http://forums.slimdevices.com/showthread.php?t=82050 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] Stereophile Review II: What conclusion can be drawn from the Measurements?
mlsstl;578491 Wrote: Having done a fair amount of analog recording with open reel over the years, I can assure you that if you have an open reel with 65 or even 70 dB of S/N, when you have a quiet passage 50 dB down, you're still in a spot where the recorded info still has only 15 or 20 dB of S/N to work with and the noise floor inserts itself into the music. That in itself represents a loss of resolution. Lost is this discussion is that quiet passages in music were meant by the composer and/or artist to be quiet. Therefore they are more subject to extraneous noise. It is meant that you have to strain or work to hear them versus turning up the volume and expecting them to sound identical to the loud passages. I find most of the defects in CD recordings were the result of intentional recording and mixing choices made by the artist, engineer or producer. I have any number of CDs that are absolutely wonderful in their dynamic range and presentation of quiet passages. If one CD can get that right, then it's not the format, and I have many. Yes I agree with most of what you say (almost anything recorded by Hyperion sounds great for example). I also note that Gramophone reviewers (who are plainly not neophiles) took to CD more enthusiastically than Hi Fi reviewers. I cannot imagine wanting regularly to listen to the slow movement of a piano sonata on record (especially not an old one.) Nevertheless the fact that CD can sound great does not mean that it can't be bettered. Also I think that there probably is something instructive to be learned from the fact that an awful lot of picky people still seem to think there is something in analog that Cd missed. I think though that the concepts of analog noise floor, dynamic range, quantisation noise and resolution need unpicking. Digital basically wins in practical terms in terms of hearing quiet sounds because its overall snr and dynamic range can easily be made greater than that of eg a record player. [But analog tapes manage to capture even if not immediately reproduce sounds below the noise floor. The notes to the later editions of Solti's Ring cycle disclose that once modern noise reduction system were applied to the old analog masters, they found all kinds of things they didn't know were there.] A digital system simply can't reproduce any sound below its quantisation noise and that quantisation noise appears throughout the amplitude range. In a digital system then the smallest value which can be given is (I think) equal to the smallest incremental value of amplitude. An analog system it seems to me may still make a very finely textured range of sounds above a noisy background. I think it is very confusing and probably inaccurate to measure the noise floor of an analog system relative to max, convert that into bits and then treat that figure as being the equivalent bit depth of the analog system for all purposes. (I think that this is because in the analog system the smallest value which can be given is not also the smallest incremental value-ie dynamic range does not equal precision. I do hope this is correct] -- adamdea adamdea's Profile: http://forums.slimdevices.com/member.php?userid=37603 View this thread: http://forums.slimdevices.com/showthread.php?t=82050 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] Stereophile Review II: What conclusion can be drawn from the Measurements?
adamdea;578475 Wrote:
I think the point that was being made [and at this point I pause to
stress that it is not my point but i am telling you what i think the
point is]
was that if you isolate the recording of a quiet sound maxing 7 bits
above digital noise floor, then this would be the same as a 7 bit
recording of this sound alone using the full dynamic range of the 7
bits. You may say that all 16/24 bits represent the quiet sound, but
there are only 7 bits worth of possible values representing this quiet
sound [I am not quite sure this is the case]. If the quiet sound had
been made much louder then it would have had the benefit not only of
being at a higher level but having been captured with greater
precision.
If you assumed that the analog sytem would be able to resove that low
level noise with infinite resolution (on the assumption that analog
recording works like an optical zoom rather than a digital zoom
[provocative or what]) then the analog recording of this sound would be
better.
OH - and I thought you were about to understand! :-)
1) all 16/24 bits represent the quiet sound, same as they do a loud
sound. The fact that several of them are zero makes no difference
except to the SNR. You have to stop thinking about bits as things in
their own right. They aren't - they are just part of a word that
represents the level (loudness) of something when you add ALL of the
bits together.
2) You also have to leave behind the digital photography analogies
because they aren't helping you to understand at all. In photography
each pixel is equivalent to a sample and has a bit-depth. BUT and it is
a MASSIVE But... when you look at a digital image you see all the
samples at once fixed in time, whereas in audio the sound is produced
by a variation in amplitude over time - that's all sound is! So in
audio, it is the change over time that matters. This is why pictures
get blocky when you zoom in - eventually you can see individual
samples - which make no visual sense in isolation.
There is NO equivalent to this in audio - without special tools (DSP)
you can't alter the timeframe in which you hear the sounds - and the
sounds themselves change (in pitch and duration) if you try. You can't
hear a single audio sample - in isolation it has no sound. You can
see a pixel.
3) I don't think you've grasped the meaning of precision vs resolution
yet. In your 7-bit example, there are NOT only 7-bits worth of values
to represent the sound... 7-bits is just what it takes to represent the
LOUDNESS of THAT sound. The fact that the higher bits have zeroes in
them doesn't mean anything for the quality of the sound other than it
is quiet so you have more chance of hearing the noise floor intrude
into it.
If the quiet sound was made louder it would be captured with the same
precision, but a greater SNR.
{upper case for emphasis]
IN LINEAR PCM, RESOLUTION IS A FIXED PRODUCT OF BIT-DEPTH. It does not
vary with volume.
In lossy compression (MP3 et al) bit-depth...and thus
resolution...varies.
4) Your optical vs digital zoom analogy is not provocative - merely
wrong :-)
Analogue sources do NOT have infinite resolution. Nor do our ears, in
fact - but that's way OT.
Tape is limited by several things, including the tape speed, tape
width, tape head gap and magnetic particle size, all of which culminate
in a finite resolution. Likewise, vinyl is ultimately limited by the
physics of both the cutter head, the replay stylus, the pressing
process and the material properties of the final vinyl - all of which
limit the accurate recording of tiny (quiet) details.
I'll casually ignore the fact that most vinyl is cut from digital
masters in the last 20+ years... :-)
Replaying quiet sounds is NOT the same as recording with less bits!
Try the SB volume control - as you wind the volume all the way down the
sound doesn't get nasty grittier like a pixellating image - it gets:
1) quieter
2) noisier
3) eventually some of the quietest parts will no longer be audible...
just like they would with any analogue source... this is simply because
they are too quiet to be heard, both in relation to the noise floor and
to the loudest parts.
--
Phil Leigh
You want to see the signal path BEFORE it gets onto a CD/vinyl...it
ain't what you'd call minimal...
Touch(wired/XP) - TACT 2.2X (Linear PSU) + Good Vibrations S/W - MF
Triplethreat(Audiocom full mods) - Linn 5103 - Aktiv 5.1 system (6x
LK140's, ESPEK/TRIKAN/KATAN/SEIZMIK 10.5), Pekin Tuner, Townsend
Supertweeters, Blue Jeans Digital,Kimber Speaker Chord Interconnect
cables
Kitchen Boom, Outdoors: SB Radio, Harmony One remote for everything.
Phil Leigh's Profile: http://forums.slimdevices.com/member.php?userid=85
View this thread: http://forums.slimdevices.com/showthread.php?t=82050
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Re: [SlimDevices: Audiophiles] Stereophile Review II: What conclusion can be drawn from the Measurements?
OGS;578474 Wrote: I may have misunderstood how this works. I have no real experience with recording live music so I appreciate the information you present Phil. If you record an acoustic trio as loud as possible with no clipping in 24bit, in a hall with medium ambient noise, then when there is no playing the level meters register around (say) -50 dB. At what digital resolution is the ambient recorded? Then you store the recording in 16bit for transfer to CD (I know, noise shaping is used to improve quality if this was to be a real product). The level of the ambient noise is still -50dB so what is the digital resolution now? 1) 24-bit PRECISION. The ambient noise will be represented by word values built from the sum of the lowest 14-15 bits. 2) 16-bit PRECISION. The ambient noise will be represented by word values built from the sum of the lowest 6-7 bits. With proper noise shaping, it will be very hard to tell the difference between the 16-bit and 24-bit versions. (actually you only get 21 bits at best from 24-bit ADC's - the rest is pure noise, but its s quiet you can't hear it) A better test is to record the same thing on 2 recorders (24 16). Again they will sound very similar... UNLESS you do any DSP after recording and before reducing to 16-bit for release. The effect of DSP (e.g. level changes) is going to benefit from the greater precision of the 24-bit source and the end result will probably sound a bit better than applying the same DSP to the 16-bit version. Basically you get less rounding errors. -- Phil Leigh You want to see the signal path BEFORE it gets onto a CD/vinyl...it ain't what you'd call minimal... Touch(wired/XP) - TACT 2.2X (Linear PSU) + Good Vibrations S/W - MF Triplethreat(Audiocom full mods) - Linn 5103 - Aktiv 5.1 system (6x LK140's, ESPEK/TRIKAN/KATAN/SEIZMIK 10.5), Pekin Tuner, Townsend Supertweeters, Blue Jeans Digital,Kimber Speaker Chord Interconnect cables Kitchen Boom, Outdoors: SB Radio, Harmony One remote for everything. Phil Leigh's Profile: http://forums.slimdevices.com/member.php?userid=85 View this thread: http://forums.slimdevices.com/showthread.php?t=82050 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] Stereophile Review II: What conclusion can be drawn from the Measurements?
adamdea;578505 Wrote: Yes I agree with most of what you say (almost anything recorded by Hyperion sounds great for example). I also note that Gramophone reviewers (who are plainly not neophiles) took to CD more enthusiastically than Hi Fi reviewers. I cannot imagine wanting regularly to listen to the slow movement of a piano sonata on record (especially not an old one.) Nevertheless the fact that CD can sound great does not mean that it can't be bettered. Also I think that there probably is something instructive to be learned from the fact that an awful lot of picky people still seem to think there is something in analog that Cd missed. I think though that the concepts of analog noise floor, dynamic range, quantisation noise and resolution need unpicking. Digital basically wins in practical terms in terms of hearing quiet sounds because its overall snr and dynamic range can easily be made greater than that of eg a record player. [But analog tapes manage to capture even if not immediately reproduce sounds below the noise floor. The notes to the later editions of Solti's Ring cycle disclose that once modern noise reduction system were applied to the old analog masters, they found all kinds of things they didn't know were there.] A digital system simply can't reproduce any sound below its quantisation noise and that quantisation noise appears throughout the amplitude range. In a digital system then the smallest value which can be given is (I think) equal to the smallest incremental value of amplitude. -If you look at John Atkinson's measurements of a sine wave in dac reviews, a good unit will make a sinewave that looks like (er) a sinewave in 24 bits. But in 16 bits even the best players can only make a squiggly thing half way between a squarewave and a sine wave. This is clear in the touch review but even clearer in the Transporter review. The cause of this as I understand it is the limited range of sample values in the 16 bit file. An analog system it seems to me may still make a very finely textured range of sounds above a noisy background. I think it is very confusing and probably inaccurate to measure the noise floor of an analog system relative to max, convert that into bits and then treat that figure as being the equivalent bit depth of the analog system for all purposes. (I think that this is because in the analog system the smallest value which can be given is not also the smallest incremental value-ie dynamic range does not equal precision. I do hope this is correct] OK - the analogue noise floor is not a hard-stop barrier, it's a sliding scale. So yes you can get back information previously buried in the analogue noise floor BUT: 1) this is ONLY possible using (24 or 32-bit) digital signal processing techniques - ironically :-) 2) the digital noise floor - whilst a hard stop - is WAY below that of the best analogue (this is particularly true of 24-bit recording) so it's less of a problem in the first place with digital!. ...and yes I've seen those sites that claim the noise floor of analogue is not as bad as it seems on the surface. Anyone who has ever ripped vinyl can come to their own conclusions on that front :-) -- Phil Leigh You want to see the signal path BEFORE it gets onto a CD/vinyl...it ain't what you'd call minimal... Touch(wired/XP) - TACT 2.2X (Linear PSU) + Good Vibrations S/W - MF Triplethreat(Audiocom full mods) - Linn 5103 - Aktiv 5.1 system (6x LK140's, ESPEK/TRIKAN/KATAN/SEIZMIK 10.5), Pekin Tuner, Townsend Supertweeters, Blue Jeans Digital,Kimber Speaker Chord Interconnect cables Kitchen Boom, Outdoors: SB Radio, Harmony One remote for everything. Phil Leigh's Profile: http://forums.slimdevices.com/member.php?userid=85 View this thread: http://forums.slimdevices.com/showthread.php?t=82050 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] Stereophile Review II: What conclusion can be drawn from the Measurements?
adamdea;578505 Wrote: ... Nevertheless the fact that CD can sound great does not mean that it can't be bettered. Also I think that there probably is something instructive to be learned from the fact that an awful lot of picky people still seem to think there is something in analog that Cd missed. I think though that the concepts of analog noise floor, dynamic range, quantisation noise and resolution need unpicking. Digital basically wins in practical terms in terms of hearing quiet sounds because its overall snr and dynamic range can easily be made greater than that of eg a record player. [But analog tapes manage to capture even if not immediately reproduce sounds below the noise floor. The notes to the later editions of Solti's Ring cycle disclose that once modern noise reduction system were applied to the old analog masters, they found all kinds of things they didn't know were there.] A digital system simply can't reproduce any sound below its quantisation noise and that quantisation noise appears throughout the amplitude range. In a digital system then the smallest value which can be given is (I think) equal to the smallest incremental value of amplitude. -If you look at John Atkinson's measurements of a sine wave in dac reviews, a good unit will make a sinewave that looks like (er) a sinewave in 24 bits. But in 16 bits even the best players can only make a squiggly thing half way between a squarewave and a sine wave. This is clear in the touch review but even clearer in the Transporter review. The cause of this as I understand it is the limited range of sample values in the 16 bit file. An analog system it seems to me may still make a very finely textured range of sounds above a noisy background. I think it is very confusing and probably inaccurate to measure the noise floor of an analog system relative to max, convert that into bits and then treat that figure as being the equivalent bit depth of the analog system for all purposes. (I think that this is because in the analog system the smallest value which can be given is not also the smallest incremental value-ie dynamic range does not equal precision. I do hope this is correct] I don't believe I ever said the CD format could not be bettered. That's not true anymore than saying the LP or open reel format is so perfect that there is no improvement possible for them. Formats are set where there are in terms of the technology available at the time. Don't you think the LP format, for example, might look a bit different if created from scratch in 2010 versus 1948? I also find the Atkinson sine wave example a bit disingenuous. Those plots are taken at a -90 dB level. There wouldn't even be a sine wave to examine at -90 dB on an LP or open reel! Sure, modern digital processing can pull information out of the muck from an old analog recording, but I think it is a bit of fanciful thinking to believe you are hearing that low level info from an unprocessed analog recording. As Phil noted, it is rather ironic that it takes DSP to even find the info. However, I try not to get wrapped up in theoretical debates on the analog vs digital subject. I've spent the last decade transferring over 2,000 LPs and open reels in my collection to digital for use with my Squeezeboxes, so I've got a serious amount of time under my belt with back-to-back comparisons. I find just as much enjoyment from the digital versions as the original analog recordings, and often more when I've been able to fix some of the glaring defects present on a LP. The other day I was listening to the ripped CD Silks and Rags by The Great American Main Street Band through my Touch. It is a stunningly well recorded, fully acoustic instrument recording. Sure, a 24/96 wouldn't hurt, but I simply can't imagine any LP or open reel of the recording giving me more enjoyment. My frank opinion is that we need to send a lot of recording engineers and producers back to school to learn to use what we already have as opposed to investing in high-rez so we can hear poor recordings in even greater detail. Just my 2 cents. -- mlsstl mlsstl's Profile: http://forums.slimdevices.com/member.php?userid=9598 View this thread: http://forums.slimdevices.com/showthread.php?t=82050 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] Stereophile Review II: What conclusion can be drawn from the Measurements?
On 09/23/2010 01:51 PM, mlsstl wrote: My frank opinion is that we need to send a lot of recording engineers and producers back to school to learn to use what we already have as opposed to investing in high-rez so we can hear poor recordings in even greater detail. Your opinion is uninformed. There is no school for producers, they are marketing people, not technical ones. The recording engineers know how to, and usually make, great sounding tracks. The Mastering engineers know how to avoid the loudness wars. Its the artists, managers, and record labels that thing that quality does not care. That folks won't pay for better quality. Its a market thing, not education. -- Pat Farrell http://www.pfarrell.com/ ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] Stereophile Review II: What conclusion can be drawn from the Measurements?
mlsstl;578550 Wrote: My frank opinion is that we need to send a lot of recording engineers and producers back to school to learn to use what we already have as opposed to investing in high-rez so we can hear poor recordings in even greater detail. Just my 2 cents. hear hear - Right on the money - but it's not the engineers. Marketing Droids... -- Phil Leigh You want to see the signal path BEFORE it gets onto a CD/vinyl...it ain't what you'd call minimal... Touch(wired/XP) - TACT 2.2X (Linear PSU) + Good Vibrations S/W - MF Triplethreat(Audiocom full mods) - Linn 5103 - Aktiv 5.1 system (6x LK140's, ESPEK/TRIKAN/KATAN/SEIZMIK 10.5), Pekin Tuner, Townsend Supertweeters, Blue Jeans Digital,Kimber Speaker Chord Interconnect cables Kitchen Boom, Outdoors: SB Radio, Harmony One remote for everything. Phil Leigh's Profile: http://forums.slimdevices.com/member.php?userid=85 View this thread: http://forums.slimdevices.com/showthread.php?t=82050 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] Stereophile Review II: What conclusion can be drawn from the Measurements?
adamdea;578505 Wrote: . -If you look at John Atkinson's measurements of a sine wave in dac reviews, a good unit will make a sinewave that looks like (er) a sinewave in 24 bits. But in 16 bits even the best players can only make a squiggly thing half way between a squarewave and a sine wave. This is clear in the touch review but even clearer in the Transporter review. The cause of this as I understand it is the limited range of sample values in the 16 bit file. An analog system it seems to me may still make a very finely textured range of sounds above a noisy background. I think it is very confusing and probably inaccurate to measure the noise floor of an analog system relative to max, convert that into bits and then treat that figure as being the equivalent bit depth of the analog system for all purposes. (I think that this is because in the analog system the smallest value which can be given is not also the smallest incremental value-ie dynamic range does not equal precision. I do hope this is correct] I missed this post. The stepped Sine wave is meaningless and does not translate into anything audible - this is part of the over-arching mega-myth of digital, which we've now discussed at some length in this thread. Information theory. Whoever first drew that wretched jagged sine wave diagram and used it to to try and explain the quantization effect of sampling was an idiot and continues to cause threads like this to exist!. A -90dB sine wave is just not there in normal music. I'd like to hear JA's justification of why he thinks this is meaningful? And, no, it's not meaningless to look at the SNR of any system, digital or analogue. Ultimately this does determine the effective resolution - ie what you can actually hear. -- Phil Leigh You want to see the signal path BEFORE it gets onto a CD/vinyl...it ain't what you'd call minimal... Touch(wired/XP) - TACT 2.2X (Linear PSU) + Good Vibrations S/W - MF Triplethreat(Audiocom full mods) - Linn 5103 - Aktiv 5.1 system (6x LK140's, ESPEK/TRIKAN/KATAN/SEIZMIK 10.5), Pekin Tuner, Townsend Supertweeters, Blue Jeans Digital,Kimber Speaker Chord Interconnect cables Kitchen Boom, Outdoors: SB Radio, Harmony One remote for everything. Phil Leigh's Profile: http://forums.slimdevices.com/member.php?userid=85 View this thread: http://forums.slimdevices.com/showthread.php?t=82050 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] Stereophile Review II: What conclusion can be drawn from the Measurements?
pfarrell;578554 Wrote: On 09/23/2010 01:51 PM, mlsstl wrote: My frank opinion is that we need to send a lot of recording engineers and producers back to school to learn to use what we already have as opposed to investing in high-rez so we can hear poor recordings in even greater detail. Your opinion is uninformed. There is no school for producers, they are marketing people, not technical ones. The recording engineers know how to, and usually make, great sounding tracks. The Mastering engineers know how to avoid the loudness wars. Its the artists, managers, and record labels that thing that quality does not care. That folks won't pay for better quality. Its a market thing, not education. I'm not particularly interested in a debate over the job title of those responsible for the general state of recordings these days. And I'm not particularly convinced that some in the industry are blameless; pressure to conform may be an explanation, but it is not a justification. However, my comment was meant as a humorous jab, not a statement of fact, so I think I'll continue indulging my uninformed prejudices. ;-) -- mlsstl mlsstl's Profile: http://forums.slimdevices.com/member.php?userid=9598 View this thread: http://forums.slimdevices.com/showthread.php?t=82050 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] Stereophile Review II: What conclusion can be drawn from the Measurements?
On 09/23/2010 03:29 PM, mlsstl wrote: I'm not particularly interested in a debate over the job title of those responsible for the general state of recordings these days. And I'm not particularly convinced that some in the industry are blameless; pressure to conform may be an explanation, but it is not a justification. If you read the trade magazines aimed at recording professionals, they are filled with pros complaining that they are forced to ruin music. When you are a working professional, and you don't do what the client wants, you are soon no longer working. Its the golden rule, he who has the gold rules. There are lots in the industry responsible, but its not because the engineers are uneducated. -- Pat Farrell http://www.pfarrell.com/ ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] Stereophile Review II: What conclusion can be drawn from the Measurements?
pfarrell;578571 Wrote: There are lots in the industry responsible, but its not because the engineers are uneducated. See the edit to my earlier comment regarding colloquialisms. When you're a participant in an industry that's sailing off course, pot shots should be expected. No different than a lawyer and lawyer jokes. Who wants to be a member of the Church of the Perpetually Offended? -- mlsstl mlsstl's Profile: http://forums.slimdevices.com/member.php?userid=9598 View this thread: http://forums.slimdevices.com/showthread.php?t=82050 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] Stereophile Review II: What conclusion can be drawn from the Measurements?
mlsstl;578574 Wrote: See the edit to my earlier comment regarding colloquialisms. When you're a participant in an industry that's sailing off course, pot shots should be expected. No different than a lawyer and lawyer jokes. Who wants to be a member of the Church of the Perpetually Offended? Chaps - chill. You are both right. Engineers know how to make great sounding records - always have done. The sad fact is that they are often not allowed to exercise their skill because the people who pay their wages won't let them... Unfortunately, he who pays the piper calls the tune. I'm pretty sure both of you guys know how to make great recordings. Just feel sorry for all those others who also know, but don't get the chance... -- Phil Leigh You want to see the signal path BEFORE it gets onto a CD/vinyl...it ain't what you'd call minimal... Touch(wired/XP) - TACT 2.2X (Linear PSU) + Good Vibrations S/W - MF Triplethreat(Audiocom full mods) - Linn 5103 - Aktiv 5.1 system (6x LK140's, ESPEK/TRIKAN/KATAN/SEIZMIK 10.5), Pekin Tuner, Townsend Supertweeters, Blue Jeans Digital,Kimber Speaker Chord Interconnect cables Kitchen Boom, Outdoors: SB Radio, Harmony One remote for everything. Phil Leigh's Profile: http://forums.slimdevices.com/member.php?userid=85 View this thread: http://forums.slimdevices.com/showthread.php?t=82050 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] Stereophile Review II: What conclusion can be drawn from the Measurements?
I while back I was doing sound for a concert that featured a number of artists and groups. This was in a venue where I designed the sound system, I KNOW how to make people sound good in this space. But there was one young lady whose manager refused to let me do my thing. He insisted that I change this, adjust that etc. I finally figured out that what he wanted was for her to sound exactly like she does on her CD, processed compressed mush. After the concert I had several people ask what happened with her, they couldn't understand a word she sang. I guess thats what the manager was after! John S. -- JohnSwenson JohnSwenson's Profile: http://forums.slimdevices.com/member.php?userid=5974 View this thread: http://forums.slimdevices.com/showthread.php?t=82050 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] Stereophile Review II: What conclusion can be drawn from the Measurements?
JohnSwenson;578595 Wrote: I while back I was doing sound for a concert that featured a number of artists and groups. This was in a venue where I designed the sound system, I KNOW how to make people sound good in this space. But there was one young lady whose manager refused to let me do my thing. He insisted that I change this, adjust that etc. I finally figured out that what he wanted was for her to sound exactly like she does on her CD, processed compressed mush. After the concert I had several people ask what happened with her, they couldn't understand a word she sang. I guess thats what the manager was after! Ooooh, go on - name names! R. -- robinbowes Net-UDAP is free software - you do not have to pay for it. However, if you found it useful, please consider donating: https://projects.robinbowes.com/Net-UDAP/trac#Donations robinbowes's Profile: http://forums.slimdevices.com/member.php?userid=480 View this thread: http://forums.slimdevices.com/showthread.php?t=82050 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] Stereophile Review II: What conclusion can be drawn from the Measurements?
pfarrell;578571 Wrote: On 09/23/2010 03:29 PM, mlsstl wrote: I'm not particularly interested in a debate over the job title of those responsible for the general state of recordings these days. And I'm not particularly convinced that some in the industry are blameless; pressure to conform may be an explanation, but it is not a justification. If you read the trade magazines aimed at recording professionals, they are filled with pros complaining that they are forced to ruin music. When you are a working professional, and you don't do what the client wants, you are soon no longer working. Its the golden rule, he who has the gold rules. There are lots in the industry responsible, but its not because the engineers are uneducated. -- Pat Farrell http://www.pfarrell.com/ +1 or 2 We know that is what is happening, it's time to let the artists know. With email or our pocketbooks. -- Nonreality -IF THE RULE YOU FOLLOWED BROUGHT YOU TO THIS, OF WHAT USE IS THE RULE.- HTTP://www.last.fm/user/nonreality Nonreality's Profile: http://forums.slimdevices.com/member.php?userid=15723 View this thread: http://forums.slimdevices.com/showthread.php?t=82050 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] Stereophile Review II: What conclusion can be drawn from the Measurements?
Phil Leigh;578530 Wrote: 1) 24-bit PRECISION. The ambient noise will be represented by word values built from the sum of the lowest 14-15 bits. 2) 16-bit PRECISION. The ambient noise will be represented by word values built from the sum of the lowest 6-7 bits. With proper noise shaping, it will be very hard to tell the difference between the 16-bit and 24-bit versions. (actually you only get 21 bits at best from 24-bit ADC's - the rest is pure noise, but its s quiet you can't hear it) A better test is to record the same thing on 2 recorders (24 16). Again they will sound very similar... UNLESS you do any DSP after recording and before reducing to 16-bit for release. The effect of DSP (e.g. level changes) is going to benefit from the greater precision of the 24-bit source and the end result will probably sound a bit better than applying the same DSP to the 16-bit version. Basically you get less rounding errors. Thanks Phil. I'll really have to re-educate myself here to understand this the right way... -- OGS Vortexbox - Touch - Tact RCS 2.0 - Rotel RB-1060 (mod) - Tannoy Sensys DC1 (mod) OGS's Profile: http://forums.slimdevices.com/member.php?userid=32981 View this thread: http://forums.slimdevices.com/showthread.php?t=82050 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] Stereophile Review II: What conclusion can be drawn from the Measurements?
mswlogo;578176 Wrote: You guys seem to think the difference between 17 and 18 bits is insignificant. It can be quite large. But when you are talking 16 vs 17 vs 18 vs 19 bits I think you are in an area that on *SOME systems with SOME rooms with SOME ears with SOME music* this can make a large practical difference. Doesn't seem that large. -- Nonreality -IF THE RULE YOU FOLLOWED BROUGHT YOU TO THIS, OF WHAT USE IS THE RULE.- HTTP://www.last.fm/user/nonreality Nonreality's Profile: http://forums.slimdevices.com/member.php?userid=15723 View this thread: http://forums.slimdevices.com/showthread.php?t=82050 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] Stereophile Review II: What conclusion can be drawn from the Measurements?
Nonreality;578196 Wrote: Doesn't seem that large. It isn't. To put this into perspective, UK BBC radio - which people used to rave about in the 70's in terms of its great sound quality on Radio 3 (the classical station) - was basically 13-bit!. One more time, it ain't the bits, it's what you do with them :-) -- Phil Leigh You want to see the signal path BEFORE it gets onto a CD/vinyl...it ain't what you'd call minimal... Touch(wired/XP) - TACT 2.2X (Linear PSU) + Good Vibrations S/W - MF Triplethreat(Audiocom full mods) - Linn 5103 - Aktiv 5.1 system (6x LK140's, ESPEK/TRIKAN/KATAN/SEIZMIK 10.5), Pekin Tuner, Townsend Supertweeters, Blue Jeans Digital,Kimber Speaker Chord Interconnect cables Kitchen Boom, Outdoors: SB Radio, Harmony One remote for everything. Phil Leigh's Profile: http://forums.slimdevices.com/member.php?userid=85 View this thread: http://forums.slimdevices.com/showthread.php?t=82050 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] Stereophile Review II: What conclusion can be drawn from the Measurements?
Phil Leigh;578198 Wrote: It isn't. To put this into perspective, UK BBC radio - which people used to rave about in the 70's in terms of its great sound quality on Radio 3 (the classical station) - was basically 13-bit!. One more time, it ain't the bits, it's what you do with them :-) Sounds like what we used to tell our girlfriends. :) And that was true too. -- Nonreality -IF THE RULE YOU FOLLOWED BROUGHT YOU TO THIS, OF WHAT USE IS THE RULE.- HTTP://www.last.fm/user/nonreality Nonreality's Profile: http://forums.slimdevices.com/member.php?userid=15723 View this thread: http://forums.slimdevices.com/showthread.php?t=82050 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] Stereophile Review II: What conclusion can be drawn from the Measurements?
mswlogo;578176 Wrote: You guys seem to think the difference between 17 and 18 bits is insignificant. It can be quite large. I agree in 24bits music most systems and ears won't hear say the bottom 5 bits or so. But when you are talking 16 vs 17 vs 18 vs 19 bits I think you are in an area that on SOME systems with SOME rooms with SOME ears with SOME music this can make a large practical difference. 17 bits seems rather poor these days. But it probably doesn't matter to folks that would use the analog outputs anyways (as opposed to a better DAC). The DACs in my 15 year old Meridian speakers can do 18bits and the 9 year ones can do 20-21 bits. I believe I can hear 18bits at normal listening levels on some passages of some music in my system that resolves 20-21 bits. I know it's more than 16 and less than 20. I clearly hear advanages of 24 bit music. But only the first couple bits are audible. But to say 17bits (in general) doesn't matter I believe is in correct. I think the argument is correct but I think it's more like 19bits it starts to not matter. I by and large agree with everything you say (except for the bit about which precise number of bits you can hear which is something I can't claim). -- adamdea adamdea's Profile: http://forums.slimdevices.com/member.php?userid=37603 View this thread: http://forums.slimdevices.com/showthread.php?t=82050 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] Stereophile Review II: What conclusion can be drawn from the Measurements?
Nonreality;578196 Wrote: Doesn't seem that large. Well it all depends on your scale. But in an audiophile context I would thinks it's huge- cf any possible benefit from different cables etc. And what's more it actually makes sense. -- adamdea adamdea's Profile: http://forums.slimdevices.com/member.php?userid=37603 View this thread: http://forums.slimdevices.com/showthread.php?t=82050 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] Stereophile Review II: What conclusion can be drawn from the Measurements?
adamdea;578263 Wrote: But in an audiophile context I would thinks it's huge... That's the problem with audiophiles, IMO - the excessive use of hyperbole. If going from a well recorded 16 bit CD recording to an 18 or 19 bit high-rez recording is huge, what word does one use to describe the difference between a transistor radio from 1963 with a 2 speaker and a well refined modern stereo? -- mlsstl mlsstl's Profile: http://forums.slimdevices.com/member.php?userid=9598 View this thread: http://forums.slimdevices.com/showthread.php?t=82050 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] Stereophile Review II: What conclusion can be drawn from the Measurements?
adamdea;578263 Wrote: If you mean the difference quantitatively- well a 19 bit number will have 8 times as many possible values as a 16 bit number. The 19 bit sample will therefore have 8 times more possible values than a 16 bit sample. adamdea;578263 Wrote: But in an audiophile context I would thinks it's huge- cf any possible benefit from different cables etc. Following the same logic, going from a sample width of googol to googol+3 must make a huge difference, I mean it will increase the resolution eightfold. -- alfista alfista's Profile: http://forums.slimdevices.com/member.php?userid=32396 View this thread: http://forums.slimdevices.com/showthread.php?t=82050 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] Stereophile Review II: What conclusion can be drawn from the Measurements?
adamdea;578263 Wrote: If you mean the difference quantitatively- well a 19 bit number will have 8 times as many possible values as a 16 bit number. The 19 bit sample will therefore have 8 times more possible values than a 16 bit sample. People seem to get excited going from SD to HD Tv which seems to me to be less than an 8 fold increase in pixels (am willing to be corrected though). As to whether the ability to play 24 bit files (even up to 19 bit resolution) makes any difference it all depends on your scale. But in an audiophile context I would thinks it's huge- cf any possible benefit from different cables etc. And what's more it actually makes sense, which is comforting. No - rgh - start again :-) Your TV analogy doesn't apply at all. Twice the pixel density = four times the file fize = 4x information. Bit depth increase from 16 to 24 = file size goes up by 50% because each number (sample) being stored is +50% more precise. The number of possible values only affects the PRECISION of each sample. It doesn't alter the amount of information, just its accuracy. The only way in which all bits are equal is that each bit gives you 6dB of Dynamic Range. When there loud stuff going on you simply can't hear the loss of the really quiet stuff. On classical music with protracted passages at -30dB... you might. The other place to look is in the reverb tails at the very end of tracks. Of course it's much MUCH easier for us to hear loud things... and very hard for us to hear quiet things happening at the same time as loud things. This is part of the reason why MP3 compression works at all. It also explains why 13-bit radio was considered state of the art (better than any available tape machine!) in the 70's and why some fairly serious test have shown that you have to reduce bit-depth to about 10 before MOST people hear a definite degradation in sound quality. ...and why Philips thought 14-bit DACs on early CD players were a good idea... 10 bits would equate to 60dB SNR which is not great - but it's about on par with good non-Dolby cassette playback... So no, the difference between 16 and 24 (21) bit playback is not huge by any way you want to measure it. The real benefits of 24-bit are: 1) greater headroom and more accurate DSP in recording / mastering = less distortion/noise - and these benefits are mostly retained after dithering down to 16-bit - if done properly. 2) the most non-linear bits are the lowest ones and they are further away from audible music in 24-bit DAC's than in 16-bit DAC's 3) A theroretically lower absolute noise floor, but as I've explained, in practice this compromised to some extent by the ADC's and other upstream equipment inthe recording chain. Probbly still worthwhile though Really it's item 1 that lets 24-bit -- Phil Leigh You want to see the signal path BEFORE it gets onto a CD/vinyl...it ain't what you'd call minimal... Touch(wired/XP) - TACT 2.2X (Linear PSU) + Good Vibrations S/W - MF Triplethreat(Audiocom full mods) - Linn 5103 - Aktiv 5.1 system (6x LK140's, ESPEK/TRIKAN/KATAN/SEIZMIK 10.5), Pekin Tuner, Townsend Supertweeters, Blue Jeans Digital,Kimber Speaker Chord Interconnect cables Kitchen Boom, Outdoors: SB Radio, Harmony One remote for everything. Phil Leigh's Profile: http://forums.slimdevices.com/member.php?userid=85 View this thread: http://forums.slimdevices.com/showthread.php?t=82050 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] Stereophile Review II: What conclusion can be drawn from the Measurements?
Many seems to believe it is signal to noise ratio or dynamic range that matters. Many will say that 16/44.1 is good enough for archiving vinyl, for example, as the s/n of vinyl is only about 70dB and CD is 96dB. But it is resolution that is important, not just s/n! You would think that 16bit is 16bit all the way down, right? After all it is called Linear PCM. Well it isn't. At -54dB ref 0dBFS 16bit we're at 7bit resolution, not 16. At -66 to -72dB where vinyl surface noise is (and maybe some tape hiss) we're at 4 to 5 bit resolution. Try recording something at 6-7bit resolution. It sounds bad! But there is vital musical information in this range. Instrument color and ambience, concert hall atmosphere. That is why 16bit depth is not good enough for acoustic music. In 24bit, -96dB is still 8bit resolution, in 16bit there is nothing but noise. Phil said it further up the thread: Phil Leigh;56 Wrote: Get a true 24-bit recording from somewhere and convert it to 16-bit in Audacity. Do they now sound the same? Do this with classical music with quiet passages. Rock music generally won't really show any differences. I believe analog more or less keeps it's resolving capacity all the way down until noise mask detail. 13bit is still 8192 distinct dynamic levels. If it is still around 13bit 40dB down, no wonder it sounded good. -- OGS Vortexbox - Touch - Tact RCS 2.0 - Rotel RB-1060 (mod) - Tannoy Sensys DC1 (mod) OGS's Profile: http://forums.slimdevices.com/member.php?userid=32981 View this thread: http://forums.slimdevices.com/showthread.php?t=82050 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] Stereophile Review II: What conclusion can be drawn from the Measurements?
OGS;578329 Wrote: Well it isn't. At -54dB ref 0dBFS 16bit we're at 7bit resolution, not 16. At -66 to -72dB where vinyl surface noise is (and maybe some tape hiss) we're at 4 to 5 bit resolution. Try recording something at 6-7bit resolution. It sounds bad! Huh? If the levels are maxed into the ADC then you are getting all the dynamic range of the LP, and then some. If the source medium is in a quiet passage then whatever resolution you're talking about (relative to its peak amplitude in THAT little section) was already lost when it was pressed. It is simply gone, and boosting the level or using a higher res ADC isn't going to bring it back. -- seanadams seanadams's Profile: http://forums.slimdevices.com/member.php?userid=3 View this thread: http://forums.slimdevices.com/showthread.php?t=82050 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] Stereophile Review II: What conclusion can be drawn from the Measurements?
The resolution and maximum SNR/DR is a fixed property of the bit-depth. What changes on a sample-by-sample basis is the SNR depending on the sample value. So a quiet passage won't have less resolution - all 16/24 bits are still being used to represent it, but it will have a lower SNR. Just like an analogue tape recorder. -- Phil Leigh You want to see the signal path BEFORE it gets onto a CD/vinyl...it ain't what you'd call minimal... Touch(wired/XP) - TACT 2.2X (Linear PSU) + Good Vibrations S/W - MF Triplethreat(Audiocom full mods) - Linn 5103 - Aktiv 5.1 system (6x LK140's, ESPEK/TRIKAN/KATAN/SEIZMIK 10.5), Pekin Tuner, Townsend Supertweeters, Blue Jeans Digital,Kimber Speaker Chord Interconnect cables Kitchen Boom, Outdoors: SB Radio, Harmony One remote for everything. Phil Leigh's Profile: http://forums.slimdevices.com/member.php?userid=85 View this thread: http://forums.slimdevices.com/showthread.php?t=82050 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] Stereophile Review II: What conclusion can be drawn from the Measurements?
You guys seem to think the difference between 17 and 18 bits is insignificant. It can be quite large. I agree in 24bits music most systems and ears won't hear say the bottom 5 bits or so. But when you are talking 16 vs 17 vs 18 vs 19 bits I think you are in an area that on SOME systems with SOME rooms with SOME ears with SOME music this can make a large practical difference. 17 bits seems rather poor these days. But it probably doesn't matter to folks that would use the analog outputs anyways (as opposed to a better DAC). The DACs in my 15 year old Meridian speakers can do 18bits and the 9 year ones can do 20-21 bits. I believe I can hear 18bits at normal listening levels on some passages of some music in my system that resolves 20-21 bits. -- mswlogo Transporter/DuetController SPDIF Meridian G68 DSP6000, DSP5500HC, DSP5000 It's the speakers and room stupid. 'My Transporter Setup' (http://forums.slimdevices.com/showpost.php?p=350741postcount=45) 'Hitch Hikers Guide to Meridian' (http://www.meridianunplugged.com) mswlogo's Profile: http://forums.slimdevices.com/member.php?userid=9090 View this thread: http://forums.slimdevices.com/showthread.php?t=82050 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] Stereophile Review II: What conclusion can be drawn from the Measurements?
So as a rank amateur, does the person that wondered why the touch review was on such a prestigious audiophile forum have credibility or does it belong maybe in the lower but still quality ranks? I would think even if I was a top notch audiophile I would want the info unless it was beneath me of course. It sounds to me like it is a nice entry level or above to the digital ways of getting music to your sound system. Entry level audiophile that is. Not just for the teaming masses like myself. -- Nonreality -IF THE RULE YOU FOLLOWED BROUGHT YOU TO THIS, OF WHAT USE IS THE RULE.- HTTP://www.last.fm/user/nonreality Nonreality's Profile: http://forums.slimdevices.com/member.php?userid=15723 View this thread: http://forums.slimdevices.com/showthread.php?t=82050 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] Stereophile Review II: What conclusion can be drawn from the Measurements?
mswlogo;578176 Wrote: You guys seem to think the difference between 17 and 18 bits is insignificant. It can be quite large. I agree in 24bits music most systems and ears won't hear say the bottom 5 bits or so. But when you are talking 16 vs 17 vs 18 vs 19 bits I think you are in an area that on SOME systems with SOME rooms with SOME ears with SOME music this can make a large practical difference. 17 bits seems rather poor these days. But it probably doesn't matter to folks that would use the analog outputs anyways (as opposed to a better DAC). The DACs in my 15 year old Meridian speakers can do 18bits and the 9 year ones can do 20-21 bits. I believe I can hear 18bits at normal listening levels on some passages of some music in my system that resolves 20-21 bits. I know it's more than 16 and less than 20. I clearly hear advanages of 24 bit music. But only the first couple bits are audible. But to say 17bits (in general) doesn't matter I believe is in correct. I think the argument is correct but I think it's more like 19bits it starts to not matter. OK - I could settle on 18-19 bits being all that is required. Touch plus good DAC can achieve 21. -- Phil Leigh You want to see the signal path BEFORE it gets onto a CD/vinyl...it ain't what you'd call minimal... Touch(wired/XP) - TACT 2.2X (Linear PSU) + Good Vibrations S/W - MF Triplethreat(Audiocom full mods) - Linn 5103 - Aktiv 5.1 system (6x LK140's, ESPEK/TRIKAN/KATAN/SEIZMIK 10.5), Pekin Tuner, Townsend Supertweeters, Blue Jeans Digital,Kimber Speaker Chord Interconnect cables Kitchen Boom, Outdoors: SB Radio, Harmony One remote for everything. Phil Leigh's Profile: http://forums.slimdevices.com/member.php?userid=85 View this thread: http://forums.slimdevices.com/showthread.php?t=82050 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] Stereophile Review II: What conclusion can be drawn from the Measurements?
Phil Leigh;577599 Wrote: The best audio ADC's in the world can only resolve 20-21 bits. The rest is pure noise. No normal microphone yet made for studio use can get much beyond a dynamic range of 100dB. The Neumann U87 - generally considered as one of the premier mics, used on tens of thousands of recordings - has a max DR of 105dB (that's about 18 bits in crude terms). However, the mic amps and desk it was plugged into (up till the 90's - and even beyond!) will eat into that. That's really all you need to know. Nobody can hear beyond the 18th bit when actual music is playing. Under normal circumstances, even the 17th/18th bits are inaudible. The importance of 24-bit (or greater) recording is NOT in the bits - it's NOT to do with the resolution/SNR. It's in the freedom you get to PROPERLY master the material. YMMV. I was under the impression that freedom to master etc was the reason why 24 bit recording is worthwhile even if CDs are being produced at 16 bit. But you seem to be saying that 16 bit (downsampled) playback of a 24 bit recording will be indistinguishable from 24 bit playback. I agree about the overall dynamic range of the recording signal and the smallest amplitude signal which can be resolved but remain unpersuaded that that is determinative of the question of what is the limit at which one can distinguish a small change in a larger signal. -- adamdea adamdea's Profile: http://forums.slimdevices.com/member.php?userid=37603 View this thread: http://forums.slimdevices.com/showthread.php?t=82050 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] Stereophile Review II: What conclusion can be drawn from the Measurements?
adamdea;577763 Wrote: I was under the impression that freedom to master etc was the reason why 24 bit recording is worthwhile even if CDs are being produced at 16 bit. But you seem to be saying that 16 bit (downsampled) playback of a 24 bit recording will be indistinguishable from 24 bit playback. No I'm not saying that. It's easy enough for you to try it and see. Get a true 24-bit recording from somewhere and convert it to 16-bit in Audacity. Do they now sound the same? Do this with clasical music with quiet passages. Rock music generally won't really show any differences. adamdea;577763 Wrote: I agree about the overall dynamic range of the recording signal and the smallest amplitude signal which can be resolved but remain unpersuaded that that is determinative of the question of what is the limit at which one can distinguish a small change in a larger signal. The Stereophile article (which I haven't read) was I thought talking about the effective resolution of the Touch analogue output maxing out at 18 bits? That would imply the noise floor of the analogue stage wipes out the bottom six bits. All I'm saying is I don't think that matters very much. This is all about noise floor, not granularity of resolution. In practice no-one could get to hear the bottom 6 bits anyway, regardless of what is in them. Sure, the noise floor of the Touch is higher than that of my DAC. But when the music is playing, I can't hear that noise... -- Phil Leigh You want to see the signal path BEFORE it gets onto a CD/vinyl...it ain't what you'd call minimal... Touch(wired/XP) - TACT 2.2X (Linear PSU) + Good Vibrations S/W - MF Triplethreat(Audiocom full mods) - Linn 5103 - Aktiv 5.1 system (6x LK140's, ESPEK/TRIKAN/KATAN/SEIZMIK 10.5), Pekin Tuner, Townsend Supertweeters, Blue Jeans Digital,Kimber Speaker Chord Interconnect cables Kitchen Boom, Outdoors: SB Radio, Harmony One remote for everything. Phil Leigh's Profile: http://forums.slimdevices.com/member.php?userid=85 View this thread: http://forums.slimdevices.com/showthread.php?t=82050 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] Stereophile Review II: What conclusion can be drawn from the Measurements?
Phil Leigh;56 Wrote: No I'm not saying that. It's easy enough for you to try it and see. Get a true 24-bit recording from somewhere and convert it to 16-bit in Audacity. Do they now sound the same? Do this with classical music with quiet passages. Rock music generally won't really show any differences. The Stereophile article (which I haven't read) was I thought talking about the effective resolution of the Touch analogue output maxing out at 18 bits? That would imply the noise floor of the analogue stage wipes out the bottom six bits. All I'm saying is I don't think that matters very much. This is all about noise floor, not granularity of resolution. In practice no-one could get to hear the bottom 6 bits anyway, regardless of what is in them. Sure, the noise floor of the Touch is higher than that of my DAC. But when the music is playing, I can't hear that noise... Phil I absolutely agree that 24 bit playback does sound better than 16 bit playback of a 24 bit file. Perhaps we have been talking at cross purposes. I assume that the reason why 24 bit files sound better is because there is information beyond the 16 bits which can make a perceptible difference. Like you i do not believe that this lies in the ability to distinguish sounds which sit below the range in which a microphone can pick them up. It is my assumtion that it is the ability to distinguish between bits 16-20 or so at levels above recoding noise floor which means that each sample is effectively more detailed. (lets call this change sensitivity -I assume that this is what you meant by granularity). It is my assumtion that this ability is somewhat limited in any DAc ie that most 24 bit DACs cannot resolve the last few bits of the message (as opposed to the noise floor) . In this case the change sensitivity of a 24 bit dac would be less than 24 bit. I also assumed that the term resolution applied to that change sensitivity as well as to the measure of the minimum amplitude of sound (in overall level) which could be picked up (say minimum level sensitivity ). So does the stereophile measurement measure the change sensitivity or only the minimum level sensitivity. If not is there a way of measuring the change sensitivity? I had assume that the measurement meant that effectively every 24 bit word was read by the touch as xx000 whereas a transporter read the words as x.. Or am I just barking up the wrong tree. I am not tryign to be awkward i have genuinely been confused for ages about why 24 bit audio sounds better, what the difference is between various dacs, and what John Atkinson's resolution measurement means. -- adamdea adamdea's Profile: http://forums.slimdevices.com/member.php?userid=37603 View this thread: http://forums.slimdevices.com/showthread.php?t=82050 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] Stereophile Review II: What conclusion can be drawn from the Measurements?
adamdea;577818 Wrote: Phil I absolutely agree that 24 bit playback does sound better than 16 bit playback of a 24 bit file. Perhaps we have been talking at cross purposes. I assume that the reason why 24 bit files sound better is because there is information beyond the 16 bits which can make a perceptible difference. Like you i do not believe that this lies in the ability to distinguish sounds which sit below the range in which a microphone can pick them up. It is my assumtion that it is the ability to distinguish between bits 16-20 or so at levels above recoding noise floor which means that each sample is effectively more detailed. (lets call this change sensitivity -I assume that this is what you meant by granularity). It is my assumtion that this ability is somewhat limited in any DAc ie that most 24 bit DACs cannot resolve the last few bits of the message (as opposed to the noise floor) . In this case the change sensitivity of a 24 bit dac would be less than 24 bit. I also assumed that the term resolution applied to that change sensitivity as well as to the measure of the minimum amplitude of sound (in overall level) which could be picked up (say minimum level sensitivity ). So does the stereophile measurement measure the change sensitivity or only the minimum level sensitivity. If not is there a way of measuring the change sensitivity? I had assume that the measurement meant that effectively every 24 bit word was read by the touch as xx000 whereas a transporter read the words as x.. Or am I just barking up the wrong tree. I am not tryign to be awkward i have genuinely been confused for ages about why 24 bit audio sounds better, what the difference is between various dacs, and what John Atkinson's resolution measurement means. Ah - I see... The Touch and the TP see the (same) bits exactly the same on their inputs. The difference is that the TP noise floor is lower so the information in the bottom bits - ONCE converted to analogue by the DAC in the TP - don't get swamped by noise. The resolution that JA is (presumably) talking about is the number of bits of music you get before the noise overwhelms them. The maximum possible is 21 with current ADC technology. -- Phil Leigh You want to see the signal path BEFORE it gets onto a CD/vinyl...it ain't what you'd call minimal... Touch(wired/XP) - TACT 2.2X (Linear PSU) + Good Vibrations S/W - MF Triplethreat(Audiocom full mods) - Linn 5103 - Aktiv 5.1 system (6x LK140's, ESPEK/TRIKAN/KATAN/SEIZMIK 10.5), Pekin Tuner, Townsend Supertweeters, Blue Jeans Digital,Kimber Speaker Chord Interconnect cables Kitchen Boom, Outdoors: SB Radio, Harmony One remote for everything. Phil Leigh's Profile: http://forums.slimdevices.com/member.php?userid=85 View this thread: http://forums.slimdevices.com/showthread.php?t=82050 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] Stereophile Review II: What conclusion can be drawn from the Measurements?
Phil Leigh;577823 Wrote: Ah - I see... The Touch and the TP see the (same) bits exactly the same on their inputs. The difference is that the TP noise floor is lower so the information in the bottom bits - ONCE converted to analogue by the DAC in the TP - don't get swamped by noise. The resolution that JA is (presumably) talking about is the number of bits of music you get before the noise overwhelms them. The maximum possible is 21 with current ADC technology. If that is the case am i now able tentatively to venture the view that the measurement indicates that the touch via analogue out will therefore not be able to deliver more than 17 bits worth of information off a 24 bit file. It seems to me that this may not be very relevant for 16 bit but means that the benefit of 24 bit files over 16 bit files will be limited. Incidentally on that measure the transporter (an unopened box containing which still sits on in my office) measures pretty close to the best tested. [Dare I say that the much vaunted Ayre QB9 is not all that great on this measurement http://www.stereophile.com/digitalprocessors/ayre_acoustics_qb-9_usb_dac/index6.html] -- adamdea adamdea's Profile: http://forums.slimdevices.com/member.php?userid=37603 View this thread: http://forums.slimdevices.com/showthread.php?t=82050 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] Stereophile Review II: What conclusion can be drawn from the Measurements?
adamdea;577829 Wrote: If that is the case am i now able tentatively to venture the view that the measurement indicates that the touch via analogue out will therefore not be able to deliver more than 17 bits worth of information off a 24 bit file. It seems to me that this may not be very relevant for 16 bit but means that the benefit of 24 bit files over 16 bit files will be limited. Incidentally on that measure the transporter (an unopened box containing which still sits on in my office) measures pretty close to the best tested. [Dare I say that the much vaunted Ayre QB9 is not all that great on this measurement http://www.stereophile.com/digitalprocessors/ayre_acoustics_qb-9_usb_dac/index6.html] Erm... you haven't sent that TP back yet? Anyway, I really really don't think this is that important for reasons I've stated several times. No 24-bit ADC available today can put the noise floor of the recording below -120dB. In practice, the noise floor is going to be -100dB (at very best). All this theory stuff is getting in the way of the music, man. Let it be. :-) -- Phil Leigh You want to see the signal path BEFORE it gets onto a CD/vinyl...it ain't what you'd call minimal... Touch(wired/XP) - TACT 2.2X (Linear PSU) + Good Vibrations S/W - MF Triplethreat(Audiocom full mods) - Linn 5103 - Aktiv 5.1 system (6x LK140's, ESPEK/TRIKAN/KATAN/SEIZMIK 10.5), Pekin Tuner, Townsend Supertweeters, Blue Jeans Digital,Kimber Speaker Chord Interconnect cables Kitchen Boom, Outdoors: SB Radio, Harmony One remote for everything. Phil Leigh's Profile: http://forums.slimdevices.com/member.php?userid=85 View this thread: http://forums.slimdevices.com/showthread.php?t=82050 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] Stereophile Review II: What conclusion can be drawn from the Measurements?
Phil Leigh;577843 Wrote: Erm... you haven't sent that TP back yet? Anyway, I really really don't think this is that important for reasons I've stated several times. No 24-bit ADC available today can put the noise floor of the recording below -120dB. In practice, the noise floor is going to be -100dB (at very best). All this theory stuff is getting in the way of the music, man. Let it be. :-) Logitech agreed to take it back and refund me. They sent an email saying they would contact me to arrange collection within 3 days (h about 10 days ago). They haven't. This is really annoying because I have already contacted them loads of times. They are very nice on the phone once you get through; then they do nothing. Mind you they have sent me a customer satisfaction form, which is slightly comical. If there is anyone listening please sort this out. -- adamdea adamdea's Profile: http://forums.slimdevices.com/member.php?userid=37603 View this thread: http://forums.slimdevices.com/showthread.php?t=82050 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] Stereophile Review II: What conclusion can be drawn from the Measurements?
adamdea;577298 Wrote: it seems to me to be a little odd to value 24 bit files as a new standard whilst dismissing a 3 bit difference in DAC resolution as irrelevant. Isn't the difference between 16 and 17 bits is more significant than the difference between 17 and an infinite number of bits? -- Soulkeeper -that is not dead which can eternal lie. and with strange aeons even death may die.- duet + boom + radio (+touch on the way) / wrt160n/dd-wrt / sbs 7.5.1 or higher/win7(32b)/avira free Soulkeeper's Profile: http://forums.slimdevices.com/member.php?userid=35297 View this thread: http://forums.slimdevices.com/showthread.php?t=82050 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] Stereophile Review II: What conclusion can be drawn from the Measurements?
seanadams;577301 Wrote: Digital cameras are a helpful analogy - more megapixels don't help much once the CCD resolution exceeds the clarity of the optics. But unless one or the other is overwhelmingly the limiting factor, we can talk about how they interplay in different scenarios. When we say a DAC can resolve so many bits, that is the same as stating its SNR, just in terms of bits instead of db. Dynamic range is a very similar concept, defined by the smallest variance in level the DAC can output that is detectable, compared to its max output level. They're measured differently but the number is usually about the same since SNR will be the limiting factor on a 24 bit DAC. Thanks. What intrigued me is this- the significance of 24 bit recording may lie in the sensitivity - of that's the right word ie the minuteness of the increments in amplitude of each sample. As a thought experiment wouldn't it be possible to have a system which purported either 0db or 140 db - I am waiting to be shot down in flames but wouldn't that have a dynamic range of 140db but 1 bit resolution ? I have read that microphones are able to achieve an snr of way less than 100db. Isnt the point of having more bits is not ultimately to allow you to hear a greater range than that but to ensure that each sample has a wider range of possible amplitudes- 2 to the power of 16 being a bit restrictive? I hope I have not got my thinking muddled. I was thinking that the difference between the smallest increment which can be distinguished within the system would be its resolution and that this would not necessarily be affected by the snr. I have been struggling with this idea for years. Perhaps what it boils down to is that if the noise floor is at -96 db will the 17 bit resolution dac and the 20 bit resolution dac have the same number of possible amplitudes for each sample within the useable space above the noise floor. I am really grateful to have you share Sean because I have for ages been puzzled over this point. -- adamdea adamdea's Profile: http://forums.slimdevices.com/member.php?userid=37603 View this thread: http://forums.slimdevices.com/showthread.php?t=82050 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] Stereophile Review II: What conclusion can be drawn from the Measurements?
adamdea;577568 Wrote: I have read that microphones are able to achieve an snr of way less than 100db. Behringer maybe :) -- michael123 michael123's Profile: http://forums.slimdevices.com/member.php?userid=23745 View this thread: http://forums.slimdevices.com/showthread.php?t=82050 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] Stereophile Review II: What conclusion can be drawn from the Measurements?
The best audio ADC's in the world can only resolve 20-21 bits. The rest is pure noise. No normal microphone yet made for studio use can get much beyond a dynamic range of 100dB. The Neumann U87 - generally considered as one of the premier mics, used on tens of thousands of recordings - has a max DR of 105dB (that's about 18 bits in crude terms). However, the mic amps and desk it was plugged into (up till the 90's - and even beyond!) will eat into that. That's really all you need to know. Nobody can hear beyond the 18th bit when actual music is playing. Under normal circumstances, even the 17th/18th bits are inaudible. The importance of 24-bit (or greater) recording is NOT in the bits - it's NOT to do with the resolution/SNR. It's in the freedom you get to PROPERLY master the material. YMMV. -- Phil Leigh You want to see the signal path BEFORE it gets onto a CD/vinyl...it ain't what you'd call minimal... Touch(wired/XP) - TACT 2.2X (Linear PSU) + Good Vibrations S/W - MF Triplethreat(Audiocom full mods) - Linn 5103 - Aktiv 5.1 system (6x LK140's, ESPEK/TRIKAN/KATAN/SEIZMIK 10.5), Pekin Tuner, Townsend Supertweeters, Blue Jeans Digital,Kimber Speaker Chord Interconnect cables Kitchen Boom, Outdoors: SB Radio, Harmony One remote for everything. Phil Leigh's Profile: http://forums.slimdevices.com/member.php?userid=85 View this thread: http://forums.slimdevices.com/showthread.php?t=82050 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] Stereophile Review II: What conclusion can be drawn from the Measurements?
adamdea;577568 Wrote: I am waiting to be shot down in flames but wouldn't that have a dynamic range of 140db but 1 bit resolution ? I think the dynamic range in that case is undefined, as you only have absolute amplitude to talk about, but yes that's the idea. And you can in fact have 1-bit DACs if they are internally oversampled to a very high rate. Most actually are some form of that internally, i.e. #8710;#8721; converters, although newer DACs are usually something like 4-bit converters at the DA stage, which might run internally at several MHz . 1-bit stored data streams even exist, i.e. DSD. And there are now 1-bit DACs that don't even convert to analog but drive a switched amplifier directly with a logic signal. Amazingly, with the required analog filter this works fine - essentially you can trade higher sample rate for fewer bits per sample to maintain the same effective dynamic range (at the low frequencies of interest), while gaining better conversion accuracy (higher SNR, lower distortion). -- seanadams seanadams's Profile: http://forums.slimdevices.com/member.php?userid=3 View this thread: http://forums.slimdevices.com/showthread.php?t=82050 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] Stereophile Review II: What conclusion can be drawn from the Measurements?
I am fascinated by these ideas, but wildly out of my depth. It occurs to mr that in the multibit PCM model what I meant might better be put this way. Assuming 4 bits to avoid too many zeros: if max = and zero = then the minimum positive signal is 0001 which is 1/15 of max. If the dac can only resolve 2 bits then 01xx is minimum signal which can be distinguished. In this case am i right that 0111, 0110, 0101 all amount to the same. 0010 0011 and 0001 all =. 1110 also = 1101. If the dac could resolve 3 bits not only would the minimum positive signal which could be resolved become 0010, but you could also now distinguish between 0110 and 0101 and between 1110 and 1100. (This would br true even with constant noise equal to 0010?) It seems to me that resolution innthis sense means the ability to distinguish between increments not only at lowest absolute level but at each level up to the top. -- adamdea adamdea's Profile: http://forums.slimdevices.com/member.php?userid=37603 View this thread: http://forums.slimdevices.com/showthread.php?t=82050 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] Stereophile Review II: What conclusion can be drawn from the Measurements?
I read today the review in Stereophile, and to my surprise, there is also one by Steven Stone in Analogue Issue of TAS. Both reviewers rave about the product, including JA's measurements But - all of them look at this piece from $300 value point. Either I missed something, but they did not compare directly against 10x-20x more expensive components. Guys went nuts to see full-features digital source for 300$ while a piece of cable will cost much more. - I could not understand how Touch sounds, absolutely and relatively to other pieces Review is more or less about technology, idea, Squeezebox server approach - and with that I absolutely agree, but there is little new that Touch brings here.. BTW, in some other magazine I saw a review of Vortexbox machine. Funny, Stereophile review mentions few upgrades like that discussed Touch Tweak blog, iPeng, John Swenson's tweak to use USB as digital out, power supply upgrade (although without mentioning Teddy Padro).. -- michael123 michael123's Profile: http://forums.slimdevices.com/member.php?userid=23745 View this thread: http://forums.slimdevices.com/showthread.php?t=82050 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] Stereophile Review II: What conclusion can be drawn from the Measurements?
adamdea;577672 Wrote: It seems to me that resolution innthis sense means the ability to distinguish between increments not only at lowest absolute level but at each level up to the top. Right, it's all the same thing. There is no special case for near 0. Indeed any offset you pick is completely arbitrary and has nothing to do with amplitude. -- seanadams seanadams's Profile: http://forums.slimdevices.com/member.php?userid=3 View this thread: http://forums.slimdevices.com/showthread.php?t=82050 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] Stereophile Review II: What conclusion can be drawn from the Measurements?
michael123;577699 Wrote: Funny, Stereophile review mentions few upgrades like that discussed Touch Tweak blog, iPeng, John Swenson's tweak to use USB as digital out, power supply upgrade (although without mentioning Teddy Padro).. This business gets its money from the same circle of people i suppose, no wonder then. Hope it isn´t such a review in that the reviewer didn´t even get what bits and bites are. Comparing a cd rip against SACD, SACD against HD download, CD against download without even checking in what the raw data differs etc. -- Wombat Transporter - RG142 - Avantgarde based monoblocks - Sommer SPK240 - self-made speakers Wombat's Profile: http://forums.slimdevices.com/member.php?userid=4113 View this thread: http://forums.slimdevices.com/showthread.php?t=82050 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
[SlimDevices: Audiophiles] Stereophile Review II: What conclusion can be drawn from the Measurements?
There have by now been many comments on the Stereophile October review which is out in US. It may not have hit UK (or other) newsagents but is available via a Zinio subscription (which was very cheap when I got it) The measurement review is on the whole positive especially bearing in mind price, but firmly nails any suggestion that the touch via analogue outs is within a million miles of the transporter. Figure 2 shows a resolution of only 17 bits whereas the transporter's was 20 bit (if I remember rightly). There is also a comment about the sinewave being nicely formed but noisy. I am not really technically literate and can only understand so much from it, but wondered if other more technically literate folk could comment as to what conclusions can be drawn In particular I don't know what conclusion if any can be drawn about the quality of the digital out. It would be very useful to know whether the noise shown in the sinewaves has any impact on the spdif output and if so where it comes from. In any event I think those measurements might form the framework for a coherent discussion of the effect of various mods/tweaks. -- adamdea adamdea's Profile: http://forums.slimdevices.com/member.php?userid=37603 View this thread: http://forums.slimdevices.com/showthread.php?t=82050 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] Stereophile Review II: What conclusion can be drawn from the Measurements?
adamdea;577163 Wrote: There have by now been many comments on the Stereophile October review which is out in US. It may not have hit UK (or other) newsagents but is available via a Zinio subscription (which was very cheap when I got it) The measurement review is on the whole positive especially bearing in mind price, but firmly nails any suggestion that the touch via analogue outs is within a million miles of the transporter. Figure 2 shows a resolution of only 17 bits whereas the transporter's was 20 bit (if I remember rightly). There is also a comment about the sinewave being nicely formed but noisy. I am not really technically literate and can only understand so much from it, but wondered if other more technically literate folk could comment as to what conclusions can be drawn In particular I don't know what conclusion if any can be drawn about the quality of the digital out. It would be very useful to know whether the noise shown in the sinewaves has any impact on the spdif output and if so where it comes from. In any event I think those measurements might form the framework for a coherent discussion of the effect of various mods/tweaks. If I get chance I'll get my scope out and have a look at the sine wave. As for not within a million miles - that's twaddle! Even if the 17 bits is correct, those last 3 bits are pretty much inaudible under normal conditions. And remember that redbook CD only has 15.5 bits anyway... You MIGHT be able to hear a difference on HDCD rendered into 20-bit or on 24-bit material...but it will be very very tiny A tiny amount of noise on the analogue output will have no bearing on the digital output. But I can't say any more until I see this noise for myself. By the way, the SB3 has a noisy analogue output, but it turned out the noise was: 1) very low level 2) very high frequency -- Phil Leigh You want to see the signal path BEFORE it gets onto a CD/vinyl...it ain't what you'd call minimal... Touch(wired/XP) - TACT 2.2X (Linear PSU) + Good Vibrations S/W - MF Triplethreat(Audiocom full mods) - Linn 5103 - Aktiv 5.1 system (6x LK140's, ESPEK/TRIKAN/KATAN/SEIZMIK 10.5), Pekin Tuner, Townsend Supertweeters, Blue Jeans Digital,Kimber Speaker Chord Interconnect cables Kitchen Boom, Outdoors: SB Radio, Harmony One remote for everything. Phil Leigh's Profile: http://forums.slimdevices.com/member.php?userid=85 View this thread: http://forums.slimdevices.com/showthread.php?t=82050 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] Stereophile Review II: What conclusion can be drawn from the Measurements?
I haven't read the review yet but if the touch is resolving 17 bits that is probably the correct maximum capability of the DAC chip. All things have a noise floor and that's what it is - and it certainly doesn't indicate anything wrong with the digital signals. Transporter has an obscenely low noise floor and it is not realistic to expect that performance from a $300 device employing a single-chip, single rail DAC + output stage. -- seanadams seanadams's Profile: http://forums.slimdevices.com/member.php?userid=3 View this thread: http://forums.slimdevices.com/showthread.php?t=82050 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] Stereophile Review II: What conclusion can be drawn from the Measurements?
seanadams;577247 Wrote: I haven't read the review yet but if the touch is resolving 17 bits that is probably the correct maximum capability of the DAC chip. All things have a noise floor and that's what it is - and it certainly doesn't indicate anything wrong with the digital signals. Transporter has an obscenely low noise floor and it is not realistic to expect that performance today from a $300 device employing a single-chip, single rail DAC + output stage. yeah so the Touch would have an effective SNR of 102dB (approx)? whereas the TP would have 120dB - is that about right? to put that into perspective... you'd have to have your amp on full and ear rammed to the tweeter to hear it (or rather, not hear it) :-) -- Phil Leigh You want to see the signal path BEFORE it gets onto a CD/vinyl...it ain't what you'd call minimal... Touch(wired/XP) - TACT 2.2X (Linear PSU) + Good Vibrations S/W - MF Triplethreat(Audiocom full mods) - Linn 5103 - Aktiv 5.1 system (6x LK140's, ESPEK/TRIKAN/KATAN/SEIZMIK 10.5), Pekin Tuner, Townsend Supertweeters, Blue Jeans Digital,Kimber Speaker Chord Interconnect cables Kitchen Boom, Outdoors: SB Radio, Harmony One remote for everything. Phil Leigh's Profile: http://forums.slimdevices.com/member.php?userid=85 View this thread: http://forums.slimdevices.com/showthread.php?t=82050 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] Stereophile Review II: What conclusion can be drawn from the Measurements?
I would be surprise if anyone expects high-end performance on analog output.. (why did you put Touch review into audiophile section, btw?) What do they tell about digital output? What I found that even digital output was far inferior to Transporter and even to 180$ m2tech device I had by chance at the time of a test -- michael123 michael123's Profile: http://forums.slimdevices.com/member.php?userid=23745 View this thread: http://forums.slimdevices.com/showthread.php?t=82050 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] Stereophile Review II: What conclusion can be drawn from the Measurements?
On 09/17/2010 02:46 PM, seanadams wrote: I haven't read the review yet but if the touch is resolving 17 bits that is probably the correct maximum capability of the DAC chip. All things have a noise floor... it is not realistic to expect that performance from a $300 device employing a single-chip, single rail DAC + output stage. Let alone recognize that 17 bits delivered is probably enough. Once you get to 100 dB SNR you are doing better than the recording chain. It can make sense to have 18 delivered just to keep the audiophile from geeking out on the meaningless numbers. ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] Stereophile Review II: What conclusion can be drawn from the Measurements?
michael123;577250 Wrote: I would be surprised if anyone expected high-end performance on analog output.. (why did you put Touch review into audiophile section, btw?) What do they tell about digital output? What I found that even digital output was far inferior to Transporter and even to 180$ m2tech device I had by chance at the time of a test was significantly better in every aspect I really don't know how you can say that, since it totally depends on what the digital output is connected to - i.e. the DAC and how well it handles incoming s/pdif or toslink. DAC's can be very different in this respect. If you hear massive differences in bit-perfect transports, your DAC is jitter and/or noise-sensitive. This isn't necessarily a bad thing - it's just something to bear in mind. -- Phil Leigh You want to see the signal path BEFORE it gets onto a CD/vinyl...it ain't what you'd call minimal... Touch(wired/XP) - TACT 2.2X (Linear PSU) + Good Vibrations S/W - MF Triplethreat(Audiocom full mods) - Linn 5103 - Aktiv 5.1 system (6x LK140's, ESPEK/TRIKAN/KATAN/SEIZMIK 10.5), Pekin Tuner, Townsend Supertweeters, Blue Jeans Digital,Kimber Speaker Chord Interconnect cables Kitchen Boom, Outdoors: SB Radio, Harmony One remote for everything. Phil Leigh's Profile: http://forums.slimdevices.com/member.php?userid=85 View this thread: http://forums.slimdevices.com/showthread.php?t=82050 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] Stereophile Review II: What conclusion can be drawn from the Measurements?
Phil Leigh;577257 Wrote: I really don't know how you can say that, since it totally depends on what the digital output is connected to - i.e. the DAC and how well it handles incoming s/pdif or toslink. DAC's can be very different in this respect. If you hear massive differences in bit-perfect transports, your DAC is jitter and/or noise-sensitive. This isn't necessarily a bad thing - it's just something to bear in mind. sure, the DAC in test was Transporter, and I think Sean himself wrote somewhere on this forum that Transporter is not forgiving.. But still.. -- michael123 michael123's Profile: http://forums.slimdevices.com/member.php?userid=23745 View this thread: http://forums.slimdevices.com/showthread.php?t=82050 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
