[SlimDevices: Audiophiles] Re: Wired vs. Wireless audio differences
you're really comparing the DAC of the CD player (or outboard DAC) with the DAC of the SB2 (assuming both deliver bit-perfect digital streams, which the SB2 may actually excel at) and (not to be forgotten), the clock jitter performance of the two transports. Since high-end audio is all about how it sounds... I can't fathom why somebody would nix blind listening testsPerhaps because they feel blind listening tests don't accurately predict how music sounds when you listen to music, rather than equipment. When your hypothesis doesn't fit the facts, you have to look closely at your hypothesis - rather than dis the facts! -- Patrick Dixon www.at-view.co.uk ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/lists/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] Re: Wired vs. Wireless audio differences
Patrick Dixon a écrit : Since high-end audio is all about how it sounds... I can't fathom why somebody would nix blind listening tests Perhaps because they feel blind listening tests don't accurately predict how music sounds when you listen to music, rather than equipment. When your hypothesis doesn't fit the facts, you have to look closely at your hypothesis - rather than dis the facts! Or you can get some facts from the medical and drug design industry and learn about placebo effect and related things. Your mind is so powerful that it can actually heal your body not only when you believe your are given an active drug, but also (in case of single blind tests) when the nurses and doctors believe your are given an active drug. Many audiophiles are pissed off because they can't tell the difference between things that sound extremely different under blind test. So they reject the facts which actually are that those things do not sound different. No fancy explanation needed here. Andy gave a very interesting explanation why the standard ABX testing methodology might 1) rely on short term memory 2) put you under a lot of stress. This might give an explanation why people fail to recognize different equipments under the ABX methodology (I'm not completely convinced, but at least there are some explanations). But, this does not apply to blind AB tests in which you level match the devices and then do what you want (listen for one full day to A and then to B, etc.). The same anti science rant was used by some psychics. Some of them refused to perform there tricks under the supervision of a magician or taped by several high rate video recorder. They claim that the bad vibes of the magician were disturbing them and other strange things. Fabrice PS: by the way, thanks a lot to sleepysurf for reporting his test results. ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/lists/listinfo/audiophiles
[SlimDevices: Audiophiles] Re: Wired vs. Wireless audio differences
When your hypothesis doesn't fit the facts, you have to look closely at your hypothesis - rather than dis the facts! Sorry should have also added: or fall back on some (possibly unrelelated) facts, that do fit your hypothesis -- Patrick Dixon www.at-view.co.uk ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/lists/listinfo/audiophiles
[SlimDevices: Audiophiles] Re: Wired vs. Wireless audio differences
pfarrell Wrote: Their website does not yet have the August issue. The do have a 15+ year old article http://www.stereophile.com/features/113/ on Blind Listening Very interesting article. The letters are very interesting too. I guess the effectiveness of blind testing depends on how different the sound is between the components tested and also on the person doing the listening. Some people obviously have better trained (or simply more gifted) ears than others. -- Aylwin ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/lists/listinfo/audiophiles
[SlimDevices: Audiophiles] Re: Wired vs. Wireless audio differences
In the interests of science, would you do another test comparing your CD player (assuming you have one) to the SB2 in a blind test. The results may be interesting! Andy. -- Andrew L. Weekes ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/lists/listinfo/audiophiles
[SlimDevices: Audiophiles] Re: Wired vs. Wireless audio differences
MrKegFlex Wrote: Just to make sure there is no confusion, I don't believe the night/day comparision was used to describe the difference between a wired and wireless connection. It was used in my post to compare the difference between my cd player and a wireless sb2. In my case, I suspect either a setup problem with the sb2, the sb2 is doing something I'm not aware of, bad lossless files, or possibly my cd player is doing something I am not aware of. Support has been quick to respond and explain that the sb2 is not doing something I am not aware of that would affect the audio, so I'm ruling that out. I have rechecked my sb2 settings and I'm pretty sure I can eliminate that variable now too. So, I'm now looking into how I created my flac/wma lossless files and my cd player specs. FWIW, in my scenario, I was able to setup a wired/wireless test last night. I did a quick 5 minute test and I couldn't tell a difference between the two. However, I have a friend swinging by this weekend and I will have him take a blind test too to see if he can hear a difference... and I plan to give the test more time than 5 minutes to sample different material. Well... on my hearing differences between my cd player and the sb2 feeding my receiver... I am now convinced I was hearing things that weren't there. Maybe, it's that phantom breakin period? I had a friend over tonight to hear the differences I was talking about and I couldn't even tell a difference when I was doing an A/B test for him. Maybe, I was trying to hear something that wasn't there when I was reviewing the sb2? Not sure but I'm now convinced that my system is performing as expected with the sb2 integrated into it. I was also able to do more wired vs wireless tests and I could not hear a difference between the two... sober and drunk. ;o) I hope sleepysurf figures out the difference in sound between the wired and wireless in his system. Don't rule out the phantom breakin period when you change something in your system, it can happen... it just happened to me with the sb2 replacing my cd player. :) -- MrKegFlex ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/lists/listinfo/audiophiles
[SlimDevices: Audiophiles] Re: Wired vs. Wireless audio differences
seanadams Wrote: I am not going to answer any more questions in this thread until someone is willing to try a blind test. It only takes a few minutes. There is no logical explanation as to why wired vs wireless should sound different. Couldn't agree more. -- Aylwin ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/lists/listinfo/audiophiles
[SlimDevices: Audiophiles] Re: Wired vs. Wireless audio differences
seanadams Wrote: I am not going to answer any more questions in this thread until someone is willing to try a blind test. It only takes a few minutes. There is no logical explanation as to why wired vs wireless should sound different. I could explain all the science behind this, but it's completely irrelevant - just let your EARS tell you. If you claim night/day differences then you should have no problem passing the Pepsi challenge. Please give it a try. Just to make sure there is no confusion, I don't believe the night/day comparision was used to describe the difference between a wired and wireless connection. It was used in my post to compare the difference between my cd player and a wireless sb2. In my case, I suspect either a setup problem with the sb2, the sb2 is doing something I'm not aware of, bad lossless files, or possibly my cd player is doing something I am not aware of. Support has been quick to respond and explain that the sb2 is not doing something I am not aware of that would affect the audio, so I'm ruling that out. I have rechecked my sb2 settings and I'm pretty sure I can eliminate that variable now too. So, I'm now looking into how I created my flac/wma lossless files and my cd player specs. FWIW, in my scenario, I was able to setup a wired/wireless test last night. I did a quick 5 minute test and I couldn't tell a difference between the two. However, I have a friend swinging by this weekend and I will have him take a blind test too to see if he can hear a difference... and I plan to give the test more time than 5 minutes to sample different material. -- MrKegFlex ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/lists/listinfo/audiophiles
[SlimDevices: Audiophiles] Re: Wired vs. Wireless audio differences
-From my understanding jitter is a time based issue that occurs when the timing on the transmission side is unstable and the DAC uses this unstable timing as a basis for conversion.- That is true. -I would presume the Squeezebox or XBMC in my case would read the FLAC file into a buffer and then send it via the digital output to the receiver where the DA conversion would take place. If this were the case as long as the buffer was never empty the wireless-ness of the transmission should not contribute to jitter in my opinion.- What you may have overlooked here is there will be jitter on the transmission interface to the DAC and it is this jitter (and this jitter only) that can cause audible degradation, depending on the DAC's jitter transfer function (i.e. how much jitter on the interface gets to the DAC clock). In the case of a Benchmark DAC1, it's none, for other DAC's it varies a lot, depending upon how well engineered they are in terms of the SPDIF interface, the receiver circuitry, the clock regeneration etc. Andy. -- Andrew L. Weekes ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/lists/listinfo/audiophiles
[SlimDevices: Audiophiles] Re: Wired vs. Wireless audio differences
These links make good reading: - http://www.benchmarkmedia.com/appnotes-d/jittercu.html lots more here: - http://www.pinkfishmedia.net/forum/showthread.php?s=threadid=10480 Andy. -- Andrew L. Weekes ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/lists/listinfo/audiophiles
[SlimDevices: Audiophiles] Re: Wired vs. Wireless audio differences
-It is very easy to verify bit-perfect output from SB2 either by playing non-PCM material or by recording with a PC.- The only problem with this (from the perspective of audible differences) is that the bit perfect test is in the digital domain, where jitter is almost irrelevant unless gross enough to exceed the SPDIF receiver's jitter limits. The conversion to analogue is where the problem arises. If for any reason the jitter spectra changes on the SPDIF, between wireless and wired operation, even if 'bit perfect', there will most likely be audible differences. I'm not saying either party is right here, since I've not yet tried it, but it's easy to think that just because it's bit perfect in the digital domain, it remains so when converted to analogue, which isn't true. Jitter only matters at the point of domain conversion, from A-D, or D-A, whereupon its effects are totally dominated by the digital receiver's jitter transfer function. Most SPDIF receivers use a single PLL, with a corner 5k, so any jiter below that remains unattenuated. Andy. -- Andrew L. Weekes ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/lists/listinfo/audiophiles
[SlimDevices: Audiophiles] Re: Wired vs. Wireless audio differences
-It is very easy to verify bit-perfect output from SB2 either by playing non-PCM material or by recording with a PC.- The only problem with this (from the perspective of audible differences) is that the bit perfect test is in the digital domain, where jitter is almost irrelevant unless gross enough to exceed the SPDIF receiver's jitter limits. The conversion to analogue is where the problem arises. If for any reason the jitter spectra changes on the SPDIF, between wireless and wired operation, even if 'bit perfect', there will most likely be audible differences. I'm not saying either party is right here, since I've not yet tried it, but it's easy to think that just because it's bit perfect in the digital domain, it remains so when converted to analogue, which isn't true. Jitter only matters at the point of domain conversion, from A-D, or D-A, whereupon its effects are totally dominated by the digital receiver's jitter transfer function. Most SPDIF receivers use a single PLL, with a corner 5k, so any jitter below that remains unattenuated. To measure the effects of jitter (on the analogue output) is quite hard to do, yet the effects are clearly audible. Andy. -- Andrew L. Weekes ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/lists/listinfo/audiophiles
[SlimDevices: Audiophiles] Re: Wired vs. Wireless audio differences
I found the following article which appears to be a good read on jitter... http://www.digido.com/portal/pmodule_id=11/pmdmode=fullscreen/pageadder_page_id=28/ However i'm still reluctant to say this is the culprit on this issue. From my understanding jitter is a time based issue that occurs when the timing on the transmission side is unstable and the DAC uses this unstable timing as a basis for conversion. I would presume the Squeezebox or XBMC in my case would read the FLAC file into a buffer and then send it via the digital output to the receiver where the DA conversion would take place. If this were the case as long as the buffer was never empty the wireless-ness of the transmission should not contribute to jitter in my opinion. -- Stric9 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/lists/listinfo/audiophiles
[SlimDevices: Audiophiles] Re: Wired vs. Wireless audio differences
Interesting comments, and link! Unfortunately, I haven't had time for more listening tests (and having to work this weekend, won't till late next week). However, I'm hoping somebody else (with more audio and technical know-how than I), can perform some OBJECTIVE measurements in the meantime. Sean, one other possibility, perhaps??? My SB2 was one of the earliest units that had the grounding issue, and I sent it back for repair. It was promptly fixed, and I might be grasping at straws here, but is it possible the repair could account for what (I think) I heard? -- sleepysurf aerius i, nht sub two, yamaha rx-v1000 (pre/pro), sunfire cinema grand 200 ~five (vertically bi-amped), squeezebox2 (streaming cd-quality audio), 300gb buffalo linkstation (remote flac audio file storage), blue jeans cables. 'Click to see pix of my system' (http://www.martinloganowners.com/~tdacquis/forum/showthread.php?t=732) ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/lists/listinfo/audiophiles
[SlimDevices: Audiophiles] Re: Wired vs. Wireless audio differences
MrKegFlex Wrote: I too am experiencing the same thing with a wireless SB2. Using flac files and connecting with digital coax to my avr is not producing the same sound as my cd player connected with digital coax to my avr. The sound is totally different... it really is a night/day difference. I have not had the opportunity to try the wired setup yet, I hope to try that setup before the end of the week. I should note that I'm on a 802.11g network. Does the software do any downsampling for a 802.11b and/or 802.11g network? -- MrKegFlex ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/lists/listinfo/audiophiles
[SlimDevices: Audiophiles] Re: Wired vs. Wireless audio differences
Easy, assuming you know your way around an audio editor: Create a small test sample (ideally a clean test tone with obvious starts and ends). Connect the SB2 via wired, connect the digital out to the digital in of your PC. Record on the PC, play on the SB2. Reconnect via wifi, repeat. Now compare the two recordings, either visually, or trim them down to exactly the same length and do a binary comparison of the resulting wav files. I'd do it myself if I had time this evening :) -- radish ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/lists/listinfo/audiophiles
[SlimDevices: Audiophiles] Re: Wired vs. Wireless audio differences
I've just switched from wired to wireless and done a few blind tests and can't hear a difference - using Rotel pre-amp/amp and Rega Jura speakers. The amp is a bit older so I'm using RCA outs from the SB2 All files are FLAC. -- bossanova808 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/lists/listinfo/audiophiles
[SlimDevices: Audiophiles] Re: Wired vs. Wireless audio differences
Check that Player Settings-Audio-Bitrate Limiting is set to 'No Limit' -- Patrick Dixon ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/lists/listinfo/audiophiles
[SlimDevices: Audiophiles] Re: Wired vs. Wireless audio differences
There must be some downsampling going on...TCP/IP is TCP/IP regardless of the transmission medium. -- radish ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/lists/listinfo/audiophiles
