iTunes and Bit Perfect vs. CD

Just got my Directstream and loving it! I set up a mac iTunes server as per the “How To” guide. I notice that the CD version (played through coaxial) has a much wider sound stage than the iTunes version (played through USB). The iTunes is AIFF at full resolution. Its almost as if the iTunes version is semi-mono sounding-sounds not bad but not nearly as good as the CD. Any thoughts?



That doesn’t sound right. I take it you are using BitPerfect with iTunes. Is BitPerfect set to PS Audio (preferences/general)? Have you tried the PSA bit perfect test files? They are in the support/downloads section. Download “DirectStream Bit Perfect Test,” unzip the files and add the 96/24 aiff file to iTunes. Mute your DS and play the file. If everything is working the DS display should show something like “bit perfect” in the upper left.

I tried the Bit Perfect test and the directstream dad stated “bit perfect” on the screen; so all is well there. The sound quality of the file being played from the computer is similar to the CD except that the sound stage and imaging is nearly gone when played from the computer. I am running the CD and the computer at the same time and switching back and forth doing an A/B. The CD is wide open with sounds floating everywhere and when you switch to the computer, it sounds like all the instruments moved to the center (literally sounds like I have a center channel). I have checked everything I could think of and the file shows stereo / 44.1 / 16 bit / AIFF… (Lee Ritenour - Smoke N Mirrors)

I will try some other material and see what happens.



Well I tried a different CD and import into iTunes; same thing… CD is a wide sound stage and the USB from computer is centered.


Very strange. It almost sounds like your speakers are out of phase but that would affect everything you played. I almost never play physical CDs anymore because my computer based audio sounds as good or better and is so much more convenient. I’m stumped as to what is going on with your system. Please keep us posted on what you find out. Just to make sure it is not something with BitPerfect you might turn it off and play without it, making sure Audio Midi Setup is set for 44/16 with output to your DS.


If i’m streaming itunes content yia the Apple Remote app from my imac to an airport express connected to my PWD via toslink, is there a role BitPerfect can or should play? Remember this setup is limited to 16/44.


I doubt it but you might want to ask the BitPerfect folks.

I bypassed Bit Perfect and ran straight through iTunes, using the suggested settings; same thing. I agree with you stevem2, its as if the speakers are out of phase with each other while playing through USB. I tried switching the speaker outputs and that did not help matters any. I’ll keep on playing with things. I really hope I can get the computer sound stage to at least match the CD - I really like the ease of library access with the iTunes.

There is definitely something wrong here so don’ give up. You might try different software to see if you get better results. Minimserver is free and you can get JRiver Media Center on a free trial basis. On the Mac side I have an early 2009 Mac Mini in my rack connected both by USB and ethernet. I have iTunes and BitPerect, which run reasonably well over USB, but I mostly use JRMC, either by USB or streaming to the Bridge. My system doesn’t sound like my speakers are out of phase with any of these.

Well, strangely, I changed the buffer to 512 in the Bit Perfect preferences and that changed things… I have 8 gigs or ram so go figure. Things seem to be sounding very good!

Excellent! It is shocking how small configuration changes can sometimes make big differences. My BitPerfect buffer is also set at 512 (I don’t think I ever changed it). Still doesn’t explain why playing directly from iTunes had the same issue.