[SlimDevices: Audiophiles] Re: Volume bug - can you really hear it?
crooner Wrote: > My experience is the opposite to peter's. > > I find the sound with my SB3 to be quite smooth with no trace of > harshness. I am using slimserver 6.2.1. > > I am using the analog outs with full volume (40) at the SB. I regulate > volume control at my receiver. > > Should I go ahead and upgrade to 6.2.2? Bear in mind I am not using the > SB's volume at all, it remains fixed at maximum level. > > Best regards, > crooner As I understand, the volume issue will not appear at full volume. It is at medium volumes where the difference is found. The curve is different, but the endpoints (lowest and highest) volumes are the same. -- LavaJoe LavaJoe's Profile: http://forums.slimdevices.com/member.php?userid=2331 View this thread: http://forums.slimdevices.com/showthread.php?t=18439 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/lists/listinfo/audiophiles
[SlimDevices: Audiophiles] Re: Why does the SB sound better than the original CD?
CardinalFang Wrote: > I was told that coax was better than optical because optical required a > conversion from electrical to optical and then back again, whereas the > coax didn't. See this thread for more comments on coax/toslink and optical/electrical conversions: http://forums.slimdevices.com/showthread.php?t=18772 Personally, I do not see the reason you state as a true reason. There'd have to be more specifics on *why* converting is necessarily "bad." Remember that coaxial cables have all sorts of "issues" to get right when passing high frequencies, like impedance matching, bandwidth limits, etc. -- LavaJoe LavaJoe's Profile: http://forums.slimdevices.com/member.php?userid=2331 View this thread: http://forums.slimdevices.com/showthread.php?t=19240 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/lists/listinfo/audiophiles
[SlimDevices: Audiophiles] Re: Squeezebox 2 - Subtle noise and distortion.
pfarrell Wrote: > On Sun, 2005-12-11 at 11:12 -0800, LavaJoe wrote: > > Problem solved! One of the bugs filed against faad2 addresses this. > > > >[snip] > > Now. It would obviously be good to get this patch into the > package > > for the future. Also, the patched version should probably be > available > > for download on the Slim web site, and this issue should be in the > FAQ > > so people can get good quality audio by using the transcoding. > > Is the patch going into the mainline sourceforge sources, by > you or someone else? Its probably wrong for everyone. > > -- > Pat > http://www.pfarrell.com/music/slimserver/slimsoftware.html Yes, it's certainly a bug. And yeah, I think this patch should go into the mainline, and the bug is only 3 days old (interesting timing), so I imagine this fix has a chance of making it. I'll email the guy and tell him of the slimserver impact. -- LavaJoe LavaJoe's Profile: http://forums.slimdevices.com/member.php?userid=2331 View this thread: http://forums.slimdevices.com/showthread.php?t=18219 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/lists/listinfo/audiophiles
[SlimDevices: Audiophiles] Re: Squeezebox 2 - Subtle noise and distortion.
slimnick Wrote: > Aha - we may have a winner. I was looking through the Linux forum and > found this post: > > http://forums.slimdevices.com/showthread.php?t=18828 > > This talks about using mplayer instead of FAAD2 to decode AAC files. > So, I've installed mplayer (using 'yum install mplayer' on my Fedora > Core 4 machine) and edited my convert.conf file to: > > mov wav * * > [mplayer] -novideo -ao pcm:file=/dev/fd/4 $FILE$ 4>&1 1>/dev/null > > And the result is what I've been looking for: a nice pure sound with no > audible disortion. One small problem though, there is a 'pop' at the > start of each track, but I'll play with the mplayer options and see if > I can't figure that out. > > So, it seems that faad2 is not the decoder of choice for Linux systems > - mplayer is. Ideally the Slimserver Wiki needs to be updated with > this, since it currently recommends using faad2 - definitely not the > right choice. > > Nick. Ah, our posts crossed in the ether... With the patched faad2, I don't hear a pop, so perhaps we can salvage faad2 afterall! Along with [perhaps] the FAQ, the Wiki should certainly contain this info. -- LavaJoe LavaJoe's Profile: http://forums.slimdevices.com/member.php?userid=2331 View this thread: http://forums.slimdevices.com/showthread.php?t=18219 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/lists/listinfo/audiophiles
[SlimDevices: Audiophiles] Re: Squeezebox 2 - Subtle noise and distortion.
slimnick Wrote:
> Elementary my dear LavaJoe! ;-)
>
> Actually, further to my previous post, I have found the following entry
> on the FAAD2 forum:
>
> http://www.audiocoding.com/modules/newbb/viewtopic.php?topic_id=151&forum=2
>
> Although this was seen on a Mac, this does seem to describe my problem
> exactly and so infers a problem with FAAD2. What is not encouraging is
> that this was reported back in 2004, so unless this is fixed in a newer
> version of FAAD2, I may have reached a dead-end with a Linux-based AAC
> Slimserver solution.
>
> So, unless there is a fix, I seem to be facing 2 options:
> 1. Convert all of my AACs to MP3 or FLAC.
> 2. Set-up a Windows server.
>
> Hmm, so much for a neat solution!
>
> Nick,
Problem solved! One of the bugs filed against faad2 addresses this. A
newline character is being written to stdout when it should be written
to stderr. I applied the change mentioned, and it produces clean
audio.
If you get the source code from:
http://sourceforge.net/projects/faac/
and build it, it will at least solve the problem. But I do not know
why this has not been fixed in the official code release.
The patch is to:
frontend/main.c, line 835
(change "printf(" to "fprintf(stderr, ")
Note that in order to build on Fedora, I had to change another file:
common/mp4ff/mp4ffint.h, line 304
(add "static " to the start of the line)
Now. It would obviously be good to get this patch into the package
for the future. Also, the patched version should probably be available
for download on the Slim web site, and this issue should be in the FAQ
so people can get good quality audio by using the transcoding.
--
LavaJoe
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[SlimDevices: Audiophiles] Re: Squeezebox 2 - Subtle noise and distortion.
slimnick Wrote: > So, I've been messing around again this afternoon and have got a little > closer to figuring out the root cause of this problem. It appears not > to be the Slimserver per se, but instead to be the act of transcoding > from AAC to another format via the stdio. > > I have performed a number of tests, with the following results: > > 1. Decode an AAC file to a WAV. > COMMAND USED: faad infile.m4a outfile.wav > RESULT: When I play the .wav using windows media player, there is no > noise. > > 2. Encode the .wav from test 1 into an MP3 manually. > COMMAND USED: lame infile.wav outfile.mp3 > RESULT: When I play the .mp3 using windows media player, there is no > noise. > > 3. Transcode an AAC to MP3 via stdio > COMMAND USED: faad -w infile.m4a | lame - outfile.mp3 > RESULT: When I play the .mp3 using windows media player, the music > plays but with the same background noise as seen when listening via my > Squeezebox and Softsqueeze. > > CONCLUSION: > From the tests above, there seems to be a limitation when transcoding > from AAC to another format via stdio. As a result, using this method of > transcoding with Slimserver will introduce an unacceptable level of > background noise. > > I will update my bug with this information, as since this is the > transcoding method Slimdevices recommend when running Slimserver on a > Linux server, I believe this is not an acceptable solution. If I can > find a way to bypass transcoding and stream the raw music off of my > server then that should hopefully solve this problem. Otherwise I'm > afraid I'll be installing Windows again... > > Nick. Hey, great slooth work! It would be interesting to try a different shell and see if that changes it. Assuming it's not the shell itself (which it probably isn't), it would be good to see whether the problem lies with faad or lame. One way would be to do (starting with known good infiles): faad -w infile.m4a | cat > outfile.wav and cat infile.wav | lame - outfile.mp3 -- LavaJoe LavaJoe's Profile: http://forums.slimdevices.com/member.php?userid=2331 View this thread: http://forums.slimdevices.com/showthread.php?t=18219 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/lists/listinfo/audiophiles
[SlimDevices: Audiophiles] Re: optical out ?
sfraser Wrote: > Not sure I believe them either . IMO, if you design a external DAC with > X amount of buffer space, you should be able to eliminate all external > jitter (jitter being time variances between data samples arrival at the > DAC input). Now once that sample is buffered you should be able to > stream it internally to the DAC, if it is designed correctly, a very > controlled environment therefore not introducing any new jitter (or > very little). In my mind a simple buffer eliminates all external jitter > and any problems it may cause. > > Regarding over/under flow of buffer space. I'm not sure that i follow. > Assuming the SB2 is the source it's providing the clocking for the data > arrival to the DAC device buffer . Even if it was clocking at bit fast, > a 64 M buffer will more than handle it in all residential applications. > 64 M of RAM purchased in bulk commercially can't run you more than a > few bucks. Less than the gold leaf writing on the front of the DAC > device (but thats marketing a real black art) .However as I stated > earlier, maybe I don't comepletly understand the problem. There were a couple of recent threads about the idea of drift over time when clocks don't match: http://forums.slimdevices.com/showthread.php?t=3697&highlight=forever+drift http://forums.slimdevices.com/showthread.php?t=17948&highlight=drift You may be right in that it may take a very long time to run out of buffer with small clock differences (and this may be far smaller than album length, giving a chance to resync periodically). But this sounds kludgy, and from a purist standpoint, if the DAC drifts from the source, the display of time, etc. on the source unit will be further and further away in time from what you are hearing. Another issue is that you'd want to full the buffer to the 1/2 way point when you start the music, so this would cause a delay proportional to the buffer size. I think that if there is a way to keep from accumulating drift and still get good results, it's preferable not to use the large buffer/two clock method. -- LavaJoe LavaJoe's Profile: http://forums.slimdevices.com/member.php?userid=2331 View this thread: http://forums.slimdevices.com/showthread.php?t=18772 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/lists/listinfo/audiophiles
[SlimDevices: Audiophiles] Re: optical out ?
sfraser Wrote: > Maybe I don't understand everything that is involved here, but I often > wondered why jitter is an issue at all between components such as a > SB2/3 and a DAC or in my case my Bryston Suround Processor preamp. If > the physical interconnect's and coax/optical cables create jitter or > timing issues, why don't more DAC's have buffer space? With the prices > companies are charging for these devices, surely a relatively cheap fix > would be to provide sufficient buffer space on your digital input of > your "DAC Device", and then re-clock? Is this to simple of a fix? > > Scott Good question, and I don't know the state-of-the-art in DACs, but the older ones definitely do try to clean up the clock using a PLL (phase-locked-loop). They have to let the source clock (the SB3, e.g.) determine the clock rate itself (in other words, you cannot have an independent clock on the DAC), since small rate differences will eventually over or underflow the buffer. A PLL uses the source signal as the clock rate, but it cleans up the jitter by evenly spacing the samples (in essense, filtering out the jitter). Audiophiles and stereo salespeople say that it's still a problem, since the more "correction" the DAC has to do to a jittery signal, the more new jitter (or residual old jitter?) is introduced indirectly. If the source is very clean, as the theory goes, the milder amount of cleanup causes fewer side effects electrically and the whole system will produce a cleaner output. The same theory is proposed to explain why even corrected errors from CDs in the transport cause degradation of sound quality - the act of correcting stresses out the system and creates jitter, electrical noise, or whatever. Not sure I really believe these theories, but that's where the whole thing goes into the realm of "hard to prove." -- LavaJoe LavaJoe's Profile: http://forums.slimdevices.com/member.php?userid=2331 View this thread: http://forums.slimdevices.com/showthread.php?t=18772 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/lists/listinfo/audiophiles
[SlimDevices: Audiophiles] Re: optical out ?
bludragon Wrote: > optical vs coax: > > http://www.audioholics.com/techtips/audioprinciples/interconnects/toslink.php > > Strange that they spec toslink at such a low bandwidth (5-10 MHz) - I > suspect, as I've read elsewhere too, that it would be the > emitter/detector pair that imposes such a low bandwidth. The upper > limit of bandwith for the optical cable itself is, of course, the > frequency of the light (10^14 Hz), but there are other factors, like > the way light bounces around in the cable, smearing the pulse edges: > > http://www.commspecial.com/fiberguide-print.htm > > Still, it's measured in MHz/km! And the lower limit they quote is a > few MHz per km. Given that toslink cables are a lot shorter than a km, > even the worst cable, I would think, would handle very high frequencies > (around 1GHz?). -- LavaJoe LavaJoe's Profile: http://forums.slimdevices.com/member.php?userid=2331 View this thread: http://forums.slimdevices.com/showthread.php?t=18772 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/lists/listinfo/audiophiles
[SlimDevices: Audiophiles] Re: Quick question: CD's per hard drive
malsbury Wrote: > If it wouldn't be much trouble, I would love to take a look at that. I > just ran into a problem with a group of files that have spaces in the > name and was trying to figure out the easiest way to replace them with > '_' > > --Tom Malsbury Sure, attached... (again, remove the ".txt" on the script). Just go to the top level dir underwhich your music lies, and type "python remove_spaces.py". I do recommend you backup before doing it. It's worked great for me, but you never know if it could hit a weird case and cause some trouble. +---+ |Filename: remove_spaces.py.txt | |Download: http://forums.slimdevices.com/attachment.php?attachmentid=535| +---+ -- LavaJoe LavaJoe's Profile: http://forums.slimdevices.com/member.php?userid=2331 View this thread: http://forums.slimdevices.com/showthread.php?t=18552 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/lists/listinfo/audiophiles
[SlimDevices: Audiophiles] Re: optical out ?
seanadams Wrote: > Further to this... physics gurus feel free to correct me: the flow of > photos can change instantaneously, whereas electrical signals have to > fight the inductance/capacitance of the cable. > > This means that any timing noise on an optical link comes only from the > transceiving modules, which according to my own tests meet or exceed the > performance of electrical links of 1m+. Sean, it's a matter of bandwidth in either case. An electrical signal can only change as fast as the fastest frequency that can travel down the cable (and this does depend on inductance/capacitance, etc. - but it's been a long time since I studied this stuff!). For an optical cable, the fastest the signal can change is the highest frequency of light that can travel down the fiber, and yeah, light in the infrared/visible range is *very* high frequency. Nothing in physics is "instantaneous" (not even photons) but you can get close! -- LavaJoe LavaJoe's Profile: http://forums.slimdevices.com/member.php?userid=2331 View this thread: http://forums.slimdevices.com/showthread.php?t=18772 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/lists/listinfo/audiophiles
[SlimDevices: Audiophiles] Re: optical out ?
PhilNYC Wrote: > Interesting, tho, that it was engineers (more than one) who gave me this > explanation... :-p I was an electrical engineer in college (you can't spell "geek" without EE!), and I don't know any basis for thinking that optical coupling is necessarily more "complex" than electrical. With electrical, you have to worry about factors like impedance, etc. And ground loops, as someone else said. I'm no expert in optical emitting technology in terms of pulse edge timing, etc., but I would think it could be done in a high-precision fashion for a digital signal if care is taken. -- LavaJoe LavaJoe's Profile: http://forums.slimdevices.com/member.php?userid=2331 View this thread: http://forums.slimdevices.com/showthread.php?t=18772 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/lists/listinfo/audiophiles
[SlimDevices: Audiophiles] Re: optical out ?
PhilNYC Wrote: > Actually, in this case it is, right? The light has to turn on and off > at nearly 44,100 times every second at a rate that allows for a sensor > to accurately read and understand. How do you make that light bulb go > from off to full intensity and then back down to completely off? Also > remember that the bulb is being turned on/off by an electrical signal. > To do this without adding jitter is certainly very complex... It would be impossible with a light bulb (the persistence/glow would be too long). With optical fiber, the emitter is an LED or laser diode, and these can be switched very fast. -- LavaJoe LavaJoe's Profile: http://forums.slimdevices.com/member.php?userid=2331 View this thread: http://forums.slimdevices.com/showthread.php?t=18772 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/lists/listinfo/audiophiles
[SlimDevices: Audiophiles] Re: Quick question: CD's per hard drive
edwin2005 Wrote: > Hm, i'm a bit of a newbie on linux (but do know my way around in dos). > Currently running an RH8 box on which i was able to get samba and > slimserver running. So if you're willing to give some explanation > together with the script (like how to run) then i would like to give it > a try. Haven't found any windhoos appl. yet to do this. I've attached my script. Please see the comments I inserted at the top of the source for information about how it works, etc. You'll probably have to make a few changes. The philosophy of this is that it mirrors the structure of the FLAC dir in the MP3 dir, but it assumes some things (like no spaces or special unix characters in filenames, etc.). BTW, I have another script that will convert your whole tree to valid filename characters if you are interested. I always recommend checking the box that converts spaces and other characters to "_" when ripping and encoding too. Makes life so much easier in Unixland! (Note that attachment is ".py.txt". Just rename it, removing the ".txt") +---+ |Filename: flacs2mp3s.py.txt| |Download: http://forums.slimdevices.com/attachment.php?attachmentid=534| +---+ -- LavaJoe LavaJoe's Profile: http://forums.slimdevices.com/member.php?userid=2331 View this thread: http://forums.slimdevices.com/showthread.php?t=18552 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/lists/listinfo/audiophiles
[SlimDevices: Audiophiles] Re: Quick question: CD's per hard drive
edwin2005 Wrote: > Hi Andy, > Would you be willing to share the script you are using to do a batch > conversion to MP3? If you are on Linux, I have a Python script that does this (transfers tags as well). You'd have to mod it a little to fit your dir structure, but it works. Let me know if you want it. -- LavaJoe LavaJoe's Profile: http://forums.slimdevices.com/member.php?userid=2331 View this thread: http://forums.slimdevices.com/showthread.php?t=18552 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/lists/listinfo/audiophiles
[SlimDevices: Audiophiles] Re: optical out ?
pfarrell Wrote: > On Mon, 2005-12-05 at 16:10 -0800, LavaJoe wrote: > > seanadams Wrote: > > > Personally I lean towards optical - if you think timing and signal > > > integrity are important in hi-fi, imagine high-capacity > > > inter-continental telecom - there's a reason it's all fiber. :) > > > Back in the Early 90s, > >[snip] > > The sales guy was very convinced that coax was far superior to > toslink. > > It was probably true back then, especially at consumer prices. > In the late 90s, home theater drove a lot of improvements > in the whole toslink space. I'd be surprized if there > is still the "far superior" difference. But YMMV and all that. > Plus coax lets you spend $200 for a "digital cable" > ahahahaha. > > -- > Pat > http://www.pfarrell.com/music/slimserver/slimsoftware.html When I bought my current speakers in 1984 (Advent Legacy models), an emblem on the box said, "Digital Ready." That made me laugh even back then! Gosh, good to have speakers that can handle a CD player...! BTW, I just refoamed the woofers in these speakers (they were suffering from the dry rot of the surround foam that happens to all speakers, I just learned), and they sound fine again. Yeah, I could do better, but it's good to make these old guys last a bit longer! -- LavaJoe LavaJoe's Profile: http://forums.slimdevices.com/member.php?userid=2331 View this thread: http://forums.slimdevices.com/showthread.php?t=18772 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/lists/listinfo/audiophiles
[SlimDevices: Audiophiles] Re: optical out ?
PhilNYC Wrote: > The reason I've heard from some engineers is that the conversion process > from one medium to another (eg. optical to electrical) is where there is > the greatest probability of adding jitter. With coax, everything stays > electrical, but with toslink, the signal must be converted from > electrical to optical and back. > > Coincidentially, one of the arguments that says a hard drive is better > than a CD is that the conversion from magnetic to electrical is far > simpler than optical to electrical... Yeah, that just silliness. There are so many complex processes going on from the magnetic platter to the output signal that it hardly matters if an an optical conversion is introduced somewhere in the chain (even if that *did* qualify as "more complex")! Sounds like classic audio salestalk to me! :) -- LavaJoe LavaJoe's Profile: http://forums.slimdevices.com/member.php?userid=2331 View this thread: http://forums.slimdevices.com/showthread.php?t=18772 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/lists/listinfo/audiophiles
[SlimDevices: Audiophiles] Re: Quick question: CD's per hard drive
Jim Wrote:
> 1 out of 3!
>
> Before everyone switches to WAV, that's 1 out of 3 hard drives I had
> failing
>
> There is a difference. Going to the trouble/time/expense of keeping a
> lossless collection and not using EAC is like drinking Johnnie Walker
> Blue Label and mixing it with coke.
Wow, that's some bad luck with hard drives...!
On the EAC issue, I agree. If you care enough to rip to FLAC/lossless,
why not make sure you get good rips? Find out the read sample offset of
your CD drive for one, and use a ripper that goes the distance to make
sure the rip is good.
I personally use grip with cdparanoia (since I use Linux). For this
combo, the only caveat is to make sure your CD drive does not cache
audio (EAC will tell you this - I tried the drive on my wife's Windows
machine to check it out). Her Sony DVD drive does cache, but my older
DVD drive (Memorex) does not cache. I've also heard that it's good for
the drive to have "AccurateStream" (EAC tells you this too).
For cdparanoia, there is an option ("-O") that is used to specify the
read sample offset correction. I have compared tracks ripped using
this flag with ones ripped with EAC and a correct offset set for the
drive it uses, and they match, proving that this option works.
The only downside to not setting read offset correctly is that your
track boundaries will be off by a very small (in the realm of
milliseconds) amount, and you will lose that same amount of data at the
start or end of the CD. But why not get it right if you can?
--
LavaJoe
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[SlimDevices: Audiophiles] Re: optical out ?
seanadams Wrote: > Personally I lean towards optical - if you think timing and signal > integrity are important in hi-fi, imagine high-capacity > inter-continental telecom - there's a reason it's all fiber. :) > > Of course coax lends itself to more impressive looking cables, but > really over short distances both optical and electrical s/pdif work > fine and show similar performance. Back in the Early 90s, I was shopping for a DAC (I ended up getting a CAL Sigma single-tube unit (I think that's what it was - I'd have to look in storage, since I don't have it in my system currently, but back then the DACs in consumer cd players were not too great, so getting a DAC could really improve things a lot)). The sales guy was very convinced that coax was far superior to toslink. If there was any truth in this, it must have been jitter (what else could it be?), but I never found out what the basis for this opinion was (of course, high-end stereo sales people tend not to use concrete reasons for good and bad). -- LavaJoe LavaJoe's Profile: http://forums.slimdevices.com/member.php?userid=2331 View this thread: http://forums.slimdevices.com/showthread.php?t=18772 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/lists/listinfo/audiophiles
[SlimDevices: Audiophiles] Re: Volume bug - can you really hear it?
Quick question: does this issue affect the bass/treble control values as well? I assume mid-level on these will cause no modification of the PCM data, whereas non-middle settings will. Or is it done in the analog domain (and analog outputs only)? -- LavaJoe LavaJoe's Profile: http://forums.slimdevices.com/member.php?userid=2331 View this thread: http://forums.slimdevices.com/showthread.php?t=18439 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/lists/listinfo/audiophiles
[SlimDevices: Audiophiles] Re: Squeezebox 2 - Subtle noise and distortion.
Patrick Dixon Wrote: > I tried > mov wav * * > with the same result as you. > > I also tried to create a > mov flac * * > entry, piping the output of faad to flac > I couldn't get that to work either, but that maybe because I didn't > really know what I was doing! Did you guys try both -f1 and -f2 flags (in faad - with respect to whether the pipe at the end expects WAV of AIF)? I wonder if it's a bigendian/littleendian (byteswap) issue. You'd get static if the sample bytes were swapped, but that's not what's going on with the Kate Bush problem. -- LavaJoe LavaJoe's Profile: http://forums.slimdevices.com/member.php?userid=2331 View this thread: http://forums.slimdevices.com/showthread.php?t=18219 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/lists/listinfo/audiophiles
[SlimDevices: Audiophiles] Re: Squeezebox 2 - Subtle noise and distortion.
slimnick Wrote: > Hi Everyone > > Looks like this problem has been reproduced a few times now under > various set-ups, so thanks again to everyone for your input into this > discussion. > > I'm going to monitor the bug I opened last week > (http://bugs.slimdevices.com/show_bug.cgi?id=2586) to see what the > software guys can deduce, and will post an update on this thread when a > solution emerges. > > Thanks again, > Nick. This is a real mystery. Something is obviously happening in the path that does not happen when one applies the same steps manually. I am personally interested in this one because it is critical (affects audio quality) and also is just plain strange! In typical computerish fashion, I'm sure the answer will be obvious once discovered. I'll continue to follow the thread with interest. -- LavaJoe LavaJoe's Profile: http://forums.slimdevices.com/member.php?userid=2331 View this thread: http://forums.slimdevices.com/showthread.php?t=18219 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/lists/listinfo/audiophiles
[SlimDevices: Audiophiles] Re: Squeezebox 2 - Subtle noise and distortion.
OK, yes, I can reproduce it, now that I've got things set up right to use faad. I get the same kind of effect that you demoed earlier in the thread (the "whooshing" noise in the background). I am using "[faad] -w -f2" in convert.conf. Using Fedora Core 4 Linux with faad2-2.0-0.lvn.5.3 and slimserver 6.2.1 - 5119 - Linux - EN - utf8. I used the same faad on the same machine to create a wav directly from the m4a, and this one plays fine. Strange, indeed...! -- LavaJoe LavaJoe's Profile: http://forums.slimdevices.com/member.php?userid=2331 View this thread: http://forums.slimdevices.com/showthread.php?t=18219 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/lists/listinfo/audiophiles
[SlimDevices: Audiophiles] Re: Squeezebox 2 - Subtle noise and distortion.
slimnick Wrote: > Interesting - especially if you do not have faad installed on your > SlimServer. My understanding is that faad is required for decoding the > AAC file. > > I have just uninstalled FAAD from my server, and after re-starting > slimserver I am unable to play any music through softsqueeze or > slimserver. The display says "PROBLEM: CANT OPEN FILE FOR:". This to me > proves FAAD is required (at least on my server) for playing AACs. > > Perhaps you have a different AAC decoder installed? > > Nick. Never Mind!!! I'm an idiot. When I played the m4a file, it must have just gone right to the wav file, and I thought it was playing the m4a file - no wonder they sounded the same! :O I got the same error, and I thought it was just a misleading error message at the start of play... I'll get back to you after I install FAAD. -- LavaJoe LavaJoe's Profile: http://forums.slimdevices.com/member.php?userid=2331 View this thread: http://forums.slimdevices.com/showthread.php?t=18219 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/lists/listinfo/audiophiles
[SlimDevices: Audiophiles] Re: Squeezebox 2 - Subtle noise and distortion.
slimnick Wrote: > Thanks Joe. I'll be unable to check this forum over the weekend, but > should be back on-line briefly Sunday night. I'll look forward to > hearing about your results. > > Nick. Hmm, OK, I just tried it. I A/B'd the two over and over, and I never heard the distinct, if any, difference that I heard in your earlier examples. In fact, there probably was no difference whatsoever, but you know how A/Bing goes. :) I used faad2-2.0-0.lvn.5.4 to convert to WAV and compared this with my SB (both played alternately on my SB3). I do not have faad installed on the Linux server that runs slimserver. It must be builtin (?). I'm currently using the nightly 6.2.1 - 5119. I'll try again on SoftSqueeze a little later. -- LavaJoe LavaJoe's Profile: http://forums.slimdevices.com/member.php?userid=2331 View this thread: http://forums.slimdevices.com/showthread.php?t=18219 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/lists/listinfo/audiophiles
[SlimDevices: Audiophiles] Re: Squeezebox 2 - Subtle noise and distortion.
slimnick Wrote: > Thanks. I did originally run Slimserver on my Windows XP PC, but > migrated it to my small Linux box when I decided I wanted an 'always > on' solution. I'm pretty sure I never heard the problem on XP, and thus > currently believe this is a Linux-only problem. Slimnick, I have a Linux-only setup, and I have not tried yet, but I will today, and I'll let you know. Indeed it's great to have an always-on system, and Linux is perfect for that. I have two Linux machines and one Windows (my wife's). One Linux is my workstation, and the other is a server in the basement, where slimserver (among other things, like email, web server, DNS, etc.) runs. -- LavaJoe LavaJoe's Profile: http://forums.slimdevices.com/member.php?userid=2331 View this thread: http://forums.slimdevices.com/showthread.php?t=18219 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/lists/listinfo/audiophiles
[SlimDevices: Audiophiles] Re: Squeezebox 2 - Subtle noise and distortion.
slimnick Wrote: > Thanks chaps for the ideas. Let me respond in turn: > > LavaJoe: I have tried a number of different AAC files from my library, > and have found that all seem to exhibit this problem. Obviously, those > with quieter audio tend to suffer worse. Being unsure of the copyright > implications of posting the entire Kate Bush AAC track to the web, I'll > hold off doing so. However, you might find that if you encode the > 'track1' sample I posted earlier into AAC using iTunes then that should > give you a sample file to work with. Thanks for offering to verify my > findings anyway. > > Nick. Yep, understood - how about just taking the first part of the WAV (like what you posted) and attaching that, both in WAV form and in ACC (make sure, first, that the ACC clip you create exhibits the problem when played through SB)? Since you posted in WMA before, and it was through the analog path, etc., I'd hate to spend time working with that. I can try the ACC quickly enough on my server if you post the snippet. Edit: (Plus, I don't have Itunes handy - I'm running Linux) -- LavaJoe LavaJoe's Profile: http://forums.slimdevices.com/member.php?userid=2331 View this thread: http://forums.slimdevices.com/showthread.php?t=18219 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/lists/listinfo/audiophiles
[SlimDevices: Audiophiles] Re: Squeezebox 2 - Subtle noise and distortion.
slimnick Wrote: > Track the bug here: http://bugs.slimdevices.com/show_bug.cgi?id=2586 I'm willing to try it on my system if you can send me the ACC file. My email is joe@(my username here).com It might be good to have another set of eyes/computer look at it. -- LavaJoe LavaJoe's Profile: http://forums.slimdevices.com/member.php?userid=2331 View this thread: http://forums.slimdevices.com/showthread.php?t=18219 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/lists/listinfo/audiophiles
[SlimDevices: Audiophiles] Re: Squeezebox 2 - Subtle noise and distortion.
slimnick Wrote: > :-) That's Kate Bush from her excellent new Album, Aerial. Ah, sounds cool! Hey, can you try this: convert the WAV to FLAC manually, load the FLAC file onto your slimserver, and try playing that (on the real SB2 as well as SS). -- LavaJoe LavaJoe's Profile: http://forums.slimdevices.com/member.php?userid=2331 View this thread: http://forums.slimdevices.com/showthread.php?t=18219 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/lists/listinfo/audiophiles
[SlimDevices: Audiophiles] Re: Squeezebox 2 - Subtle noise and distortion.
slimnick Wrote: > Thanks guys for the ideas - I'll give this a try. > > Meanwhile, in case want to hear what the problem really sounds like, > here's a couple of short samples: > > http://myweb.tiscali.co.uk/textengine/slim/track1.wma > http://myweb.tiscali.co.uk/textengine/slim/track2.wma > > I have recorded these by linking the analogue out of my PC to the line > in; playing the tracks using softqueeze; and recording using the > Microsoft plus analogue recorder. > > Track 1 is the wav file I converted using faad from the original AAC. > Track 2 is the original AAC. > > Unfortunately I could only record the right channel due to a lack of > cables, but you can certainly hear the problem clearly in channel 2. > > Does this give anyone any clues? > > Thanks > Nick. Wow, very audible! More white-noise-like than what I was describing (my digital noise/"pattern" was more tonal, and I'm wondering if it might be EMI). Yours sounds like some movie sound effect... Am I thinking of "Contact?" Who's the artist? -- LavaJoe LavaJoe's Profile: http://forums.slimdevices.com/member.php?userid=2331 View this thread: http://forums.slimdevices.com/showthread.php?t=18219 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/lists/listinfo/audiophiles
[SlimDevices: Audiophiles] Re: Squeezebox 2 - Subtle noise and distortion.
Patrick Dixon Wrote: > Slimserver 'contains' FLAC. If it is streaming as FLAC, I think it uses > mov123 (part of quicktime?) and FLAC. You can control what it converts > to what by going to Server Settings -> File types and playing with the > checkboxes. Ah, more variables to try! Yeah, it would be good to trace this down to whether streaming auto-FLAC-converted WAV files sound the same as raw streamed WAV files. If they do, then it must be the ACC decoding part... -- LavaJoe LavaJoe's Profile: http://forums.slimdevices.com/member.php?userid=2331 View this thread: http://forums.slimdevices.com/showthread.php?t=18219 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/lists/listinfo/audiophiles
[SlimDevices: Audiophiles] Re: Squeezebox 2 - Subtle noise and distortion.
slimnick Wrote: > Hi Patrick > > Sorry to taint the pristine audiophiles section with my grubby AAC > problems. ;-) I'm new to the forum and did wonder whether instead I > should have posted this in the general discussion. Is there any way I > can get this thread moved there? > > Regarding your suggestions, I am not transcoding the audio to MP3 - I > have set rate limiting to 'no limit' which should simply decode the > AACs via FAAD and then send the raw output across my network. I did > wonder if I had a problem with FAAD, but as I mentioned previously, if > I use FAAD at the command line to decode an AAC into a WAV, and then > play that in Windows Media Player on my Windows PC, the quality is > fine. However, for some reason Softsqueeze and Slimserver 2 seem to be > having problems handling the output from FAAD when Slimserver decodes > the AACs. > > I would have thought that my set-up is reasonably typical for anyone > integrating an iTunes library into Slimserver, so I'd certainly be > interested if anyone else is able to reproduce my symptoms. > > Thanks > Nick. Have you tried putting the WAV files you generated on the slimserver and playing them over SB and SoftSqueeze? It does sound like either the FAAD processing or the on-the-fly FLAC conversion (or the FLAC decoding in SB/SS - I hope not!). Trying the "good" WAV files on slimserver would at least eliminate the FLAC part as a culprit. -- LavaJoe LavaJoe's Profile: http://forums.slimdevices.com/member.php?userid=2331 View this thread: http://forums.slimdevices.com/showthread.php?t=18219 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/lists/listinfo/audiophiles
[SlimDevices: Audiophiles] Re: Squeezebox 2 - Subtle noise and distortion.
If I pause the SB2 and turn up the amp volume, I can hear a "digital noise" too - and it doesn't have to be that load. I also was wondering if this was normal. I tried the pause test because I thought I could here low-level noise/distortion once during music play (it was Jazz, with quiet spots). I know some one-bit DACs can produce patterned noise while "idle," and I have not investigated further by playing an all-zero sound file yet to see if the problem happens when unpaused... -- LavaJoe LavaJoe's Profile: http://forums.slimdevices.com/member.php?userid=2331 View this thread: http://forums.slimdevices.com/showthread.php?t=18219 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/lists/listinfo/audiophiles
