reedermw

At the risk of sounding completely insane, I ran into something unexpected tonight. I was browsing my music file and discovered that if you press the space bar on a file, it will play it. The player that plays the file isn't iTunes however. It is apparently a preview program built into the Finder app itself. If I had to guess, I would say it was QuickTime. To my surprise however, the sound quality was excellent. I found that I preferred it over iTunes or the other assorted players I've tried. The sound stage is very open and involving somehow. Does anyone know what this program actually is? Has anyone discovered this as well? I'm running Snow Leopard (10.6.3) with the latest version of iTunes installed.

My apologies if this has been beat to death already. I searched the forums but didn't find a discussion on it. I'm using Win7 with a USB DAC and recently played an Apple Lossless file via VLC and noticed that it sounded a lot better than the same file played back in iTunes. I checked QuickTime Audio and it's set to Windows Session (WASAPI). I found that changing the Default Synthesizer to General Midi (from QuickTime Music Synthesizer) improved the sound of iTunes quite a lot but it's still not as good as VLC. In comparison, VLC just seems clearer especially in the mid to upper frequencies. Has anyone else run into this? Is VLC better or is the latest 10.6 version of iTunes messed up somehow?

I just ran into something interesting last night that I haven't seen discussed here. In Windows, QT is used to play back the files and I have always set the QT audio output to Windows Audio Session (WASAPI). But there is another option on that same dialog panel called "Music Synthesizer". By default it's set to "QuickTime...". I changed this option to "General Midi" and it dramatically improved the sound. It's less muddy for lack of a better term. I had all but given up on iTunes because the sound quality was lacking but this option seems to make it competitive again. Has anyone run into this before or is it just something unique to my setup? I am running this on a Mac mini running Windows 7 32-bit>USB>Emotiva XDA-1 DAC.

I recently installed XBMC on my Apple TV. It is done fairly easily via a USB flash drive. It's nice because it leaves the existing Apple TV software in place and just adds itself to the main Apple TV menu. Once the XBMC app is launched from the Apple TV main menu, it takes over the the full screen and essentially replaces the functionality of the native software. When you exit/shutdown XBMC is just returns to the Apple TV main menu. I found a couple problems that I'll pass on for those interested in trying it. You must set your resolution in Apple TV to 720p prior to using XBMC. If you are using 1080i (which I was) XBMC doesn't seem to format properly and getting it switched back is difficult. Other than that, it has been a dream to work with. I never exit back to the native Apple TV software anymore. It supports almost any video and audio file format. I really like being able to just browse my NAS for files instead of having to connect to a running instance of iTunes on another machine. It will connect to network shares and also has a UPnP client built it to connect to devices with UPnP AV Servers. The latest version 9.04 (Babylon) has removed the re-sampler and outputs bit-perfect data for AIFF, ALAC and FLAC. It can also handle AC3 streams with DD and DTS and send them on to a processor for decoding. Note that when it plays back AIFF, ALAC and FLAC it outputs 16/44 but when outputing AC3 DD or DTS streams, they output in 16/48. Audio performance seems a bit cleaner/clearer with XBMC than native Apple TV. I'm not sure why. The Apple TV natively sounds excellent but XBMC just sounds a little more natural with a bit more depth or layering. I realize that it should be identical to Apple TV ALAC output but it seems slightly better. You'll have to try it and judge for yourself. I use the Apple TV/XBMC 9.04 (Babylon) combo as my audio source in my hi-end setup and have been very happy with it. Sadly, my nice DAC doesn't do HDCD decoding so I'm unable to confirm the bit perfect output from it for ALAC, AIFF, FLAC files. Perhaps someone else will try it and let us all know. Apple TV runs a stripped down version of OS X and XBMC runs as a native app on top of it so would that indicate that there is a good chance of it being bit perfect? I ran across a very nice article on XBMC/Plex audio output here: http://elan.plexapp.com/2008/11/11/plexseven-new-coreaudio-output-module/

Squeezebox streaming from SqueezeCenter DOES bypass the kmixer on Windows XP. For more info: http://www.avsforum.com/avs-vb/showthread.php?t=947502

I spent months with both XP and Vista and can confirm that they sound quite different. I tried many different programs and drivers and ended up with a USB DAC to bypass the KMixer alltogether. Even so, I noticed a difference between XP and Vista. So the way that QuickTime works on Vista vs XP appears to be different. I don't have access to the source or the ambition to figure it out. I eventually moved to the Apple TV because it took all those variables out of the equation. The Apple TV runs OS X and the player is native to it. So assuming that one likes the sound that it produces, it buys a lot of flexibility on how the files are actually hosted. Since I work on computers for a living, my PC's around the house change frequently and I didn't want my audio setup to change every time changed the hosting box. The SB does the same thing if you are willing to use AIFF or FLAC. ALAC on SB is questionable since it uses QuickTime on the SqueezeCenter box to decode it, the resulting sound quality of an ALAC file played by a SB can be dependent on the OS hosting your files (I think). Since I would rather manage my lib with iTunes, it made my choice an easy one.

>> "I've tested the Apple Airport Express and Apple TV. >> Both are bit perfect via the digital output." >> >> __________________ >> >> Chris Connaker >> >> Founder >> Computer Audiophil Chris, Did you confirm using AIFF, WAV or ALAC files from the Apple TV?

Nice explanation Fyper. That matches my understanding as well. Since I am using Windows XP as my iTunes/media server I have to be concerned about KMixer and it's altering of audio data. The Apple TV runs a stripped down version of OS X and I would hope it would play back files and output bit-perfect data. The lingering question for me is this--if I am using "shared music" mode on the Apple TV, does this mean that the Apple TV is just copying the ALAC file down and playing it back through it's own player/codecs? If so, then it should be bit perfect playback. If on the other hand, it's using QuickTime on the XP box to playback the ALAC file and sending the output to the ATV, then the output would not be bit perfect. Am I safe to assume that since the ATV run OS X and has it's own player that it's outputting bit perfect data even though the data is coming from iTunes running on XP? The SqueezeBox on the other hand doesn't handle ALAC natively meaning that SqueezeCenter would have to be using QuickTime on XP to playback the file. So would I be correct that the output from the SqueezeBox where SqueezeCenter is running on XP would not be bit perfect. If so, it would seem that one would want to use FLAC on SqueezeBox and ALAC on ATV if lossless compression was desired as well as bit perfect output.

Here's a discussion of the new ALAC encoder: http://forums.ilounge.com/showthread.php?p=1326500 I performed a pretty interesting test tonight. I took one of my existing ALAC encoded files (ripped some time back with 8.0) and converted to AIFF using iTunes. The resulting AIFF file sounds correct and doesn't have any of the previous problems that I found with the ALAC version. This conversion was done with 8.1.1 of iTunes. And here is where it gets really weird, I converted this AIFF file back to ALAC using iTunes 8.1.1 and the resulting new ALAC file sounded perfect. I changed the track title of each by appending (ALAC) to the original and (ALAC2) to the newly encoded file so that I could easily identify both in Apple TV's interface. I can AB both of these files now and the older ALAC file sounds off and the new one sounds correct. Thinking that I had completely lost it, I re-ripped the CD again just to make sure that I wasn't hearing things (pun intended). I believe ALAC is now fixed in iTunes 8.1.1 and I think all I have to do is mass re-encode using iTunes to fix them up. So that's good news but, wow, what could possibly have changed? The file sizes and bit rates are different between the old and new. Perhaps it's header/tag data that controls the decoder that was changed rather than the PCM data itself?!? I don't see how the compressed PCM data could be different. There have been many tests confirming bit perfect output. An HDCD rip that lights the HDCD decoder on a DAC/Receiver, etc. How else could I convert an old ALAC to an AIFF and have it sound correct and then convert that file to a new ALAC and have it fixed. This tells me that either the changes made in the new encoder are header/tag data that controls the decoder or all my ALAC files are not really/truely lossless and mass converting them in iTunes to the new ALAC will make them sound correct but they won't be the same as a re-rip. The thought of spending the next 6 months re-ripping all my CD's is unbearable so I'll not even consider it.

Interesting comment. The post above where they discovered that a file stored locally on the ATV sounded better than streaming may due to a test where they were using the ATV as an AirTunes receiver (push rather than pull) and if the file were being played by iTunes on XP that could account for the differences. A file stored locally on the ATV should be played back by the software on the ATV (OS X). It would be interesting to know if the test referred to in the previous post was done in this fashion or not. I have shared my iTunes lib on the XP box and access it from the ATV as "Shared Music" (pull). I believe this still has the ATV player decoding the file and thus bypassing the XP KMixer but then I'm not exactly sure how the data is being transmitted. Hopefully they don't run it through the QuickTime engine on the box sharing the lib. I'm not sure how to even test this. I will say that the sound quality of an AIFF being streamed down to an ATV from iTunes running on an XP box (as "Shared Music") is as good or better than a good CD transport. So this may be an advantage that ATV has over AE if one is using XP.

I performed a simple test tonight that you can easily recreate in your own setup to confirm it. I ripped a track from Keiko Matsui (especially well recorded redbook audio CD's) in WAV, then in AIFF and finally in ALAC. All 3 are lossless formats so you can rip to one like AIFF then change the import setting to a new format, right click on the track and select "Convert to ...", repeat and rinse for the other formats. I am streaming from iTunes 8.1.1 running on a Windows XP box to the Apple TV using a wired (no WiFi) connection. To make matters easier, I renamed the track title of each song by appending (AIFF), (ALAC) or (WAV) to it so I would know what I was playing back on the Apple TV. The AIFF and WAV files sounded identical and also matched both CD transports that I have. The ALAC file however sounded different. The overall tonal balance was brighter/higher almost like the entire recording was shifted up one octave in frequency. The dynamic range also seemed about 10db more narrow making softer sounds that would normally be well in the background more forward and apparent. The recording in general took on a brighter more detailed slightly louder presentation. The affect of this change varies greatly from track to track and may not be noticeable on some recordings. Keiko Matsui's albums are well recorded and never sound bad even when altered by the ALAC decoder on the Apple TV but while they seem to reveal more detail they also seem to lack some emotional impact at the same time. My results have convinced me that the ALAC decoder in the Apple TV software is different than AIFF and WAV. This leaves me in somewhat of a quandary because I was hoping to store my library in ALAC format but now I'm inclined to put it in AIFF. AIFF is basically WAV with tags that can be used for indexing. WAV in won't work for me because while iTunes will record the info in it's database, there are no tags stored in the files so if I ever have to rebuild my library, it won't be tagged. I don't think the above results would vary based on the OS that hosts iTunes. I don't have a Mac in the house at the moment to prove it but I believe that the ALAC decoder and settings are embedded in the software running on the Apple TV with the shared iTunes library being little more than a file share over Apple's Bonjour peer-to-peer protocol. Imagine the Apple TV as nothing more than a stripped down Mac running OS X and iTunes and you get pretty close. So you guys using Apple TV's in your high end setups--are you using AIFF then? I think the Apple TV playing back AIFF is slightly better than either of my two CD transports perhaps due to less-than-perfect error correction required by CD playback. So the Apple TV bests a $2400 CD transport so I'd say it's a pretty good bargain. Still I'm not crazy about converting all my ALAC files back to AIFF. Maybe Apple will fix this for us audio geeks.

The Apple TV is basically an iPod for your hifi rig. It has either 40gb or 160gb of storage that you can sync content to from iTunes running on another computer. Additionally, you can share your iTunes library and the Apple TV will browse and stream the content without having to download any of it. This works exactly like shared iTunes libraries between two computers in your house.

I have been AB testing Apple TV against a number of CD transports of sufficient quality. The CD transports are using the same optical cable as the Apple TV and going into the same DAC. The Apple TV simply reveals more sound especially the quieter sounds normally somewhat lost in the background. While ATV sounds good to me, it also sounds like it's achieving it's results through dynamic range compression, making some background sounds more noticeable than other transports. I am using ALAC streaming to the ATV rather than stored locally. The other rather interesting thing that happens is that the layering of sound actually appears to be different. Comparing the two on some tracks gives a very different interpretation of the same song. Perhaps this is a result of it being in ALAC format? Lossless should be lossless, so I find that very confusing. If I stream AIFF and it transcodes to ALAC on the fly than it should sound the same as an ALAC file (which it seems to for me). If storing an AIFF locally however sounds better, than perhaps there is something fishy with ALAC. The device also supports video so perhaps they do implement some form of dynamic range compression to aid in movie playback and only apply to specific formats? At any rate, it does sound different and given that ALAC is supposed to be lossless, it shouldn't. I'm using a Windows XP box to stream from. The idea that it could be different if using a Mac is also quite confusing. I second the comment above, "something fishy is going on here...".

I'm glad to see there is a site dedicated to digital streaming info. I have heard that Squeezebox is better quality than Apple TV from a number of different sources. I contacted Bolder Cable to check into their mods for the SB and he mentioned that SB was clearly superior. However, in my own tests, I have not found this to be true. The Toslink output of the Apple TV in my setup is much higher quality than either coax or optical out of the SB. <br /> <br /> I have tried 2 different DAC's and confirmed the findings in both cases. I'm using some highly resolving Magnepan speakers so maybe I can hear the differences more, I'm not sure. Ironically, I think the difference may be jitter on the stock SB because I'm losing high frequency detail and those mis-aligned samples are dropping into the audible bass region making it muddy. <br /> <br /> I think the only way to get the SB to sound as good as the ATV would be to pair it with a re-clocking DAC or upgrade the power supply in the SB. I'm not inclined to invest another $1k into upgrading the SB. So in spite of all the info to the contrary, the ATV is the better network transport than the stock SB Classic. <br /> <br /> Have any of you run into this? Perhaps a better DAC would compensate for the differences and allow either to perform equally well? Given that I like the sound of DAC, I'll likely sell the SB Classic and just use the ATV.<br /> <br /> Here's some more detail of my AB tests:<br /> <br /> I'm using Apple Lossless encoded files for the AB tests. One difference is that the ATV decodes the ALAC files natively while the SB decodes them on a SqueezeCenter server and streams down WAV or FLAC (I've tried both). Perhaps the data is being compromised before it reaches the SB? So I re-ripped my test CD's in FLAC for the SB and AB'd ALAC/ATV vs FLAC/SB and the ATV still beat it.<br /> <br /> I have tested both SPDIF outputs on the SB. The Coax is much better than the Toslink but still not equal to the Toslink of the ATV. I'm using the same cables in both cases wherever possible.<br /> <br /> I have tested with 2 different DAC's and while the sound was different, the ATV still bested the SB.<br /> <br /> So here's my question--have any of you found the quality lacking in the Squeezebox Classic or am I missing something? Do you think my DAC's are the issue? I'm sure I'll get flamed for suggesting that the ATV is better sounding than the SB but that is my finding.