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Airport Express wav file vs CD played thru iTunes

I just bought an Airport Express and have it connected to my Primaluna integrated without using an external DAC (for the time being).

When I stream a wav file from iTunes the sound quality is noticeably worse than the same track played on a CD through iTunes. The wav file sounds compressed and very muffled. I would expect the quality to be equal to the CD. I only did this as a test and don't expect to play CDs through iTunes on my laptop streaming to the AE.

Will an external DAC "correct" this problem? Or is the wav file encoder for iTunes the issue? Or maybe something else entirely?
arm
arm OP
2 posts
 
WAV files are uncompressed and should be of the same quality as a CD, no?
sfar's avatar
sfar
1,768 posts
 
I'm streaming wirelessly from iTunes on an iMac G5 through an Airport Express connected by glass toslink to a Benchmark DAC1 and then to my amplifier.

WAV files, which, as Arm said, are uncompressed, Apple Lossless files and AIFF files, which are what you find on CD's, are indistinguishable from each other. MP3 and other compressed formats don't sound as good, though MP3's at the higher bit rates aren't bad.
ckoffend
684 posts
 
The one thing you have indicated that could be involved with the sound quality is when you indicate:

"is the wav file encoder for iTunes the issue?"

My question to this is are you ripping your CD to your computer using a WAV lossless file then importing this file into iTunes? While I am no expert on iTunes (don't much care for it personally), I thought when a file was converted and brought into iTunes it became an MP4 (which is compressed).

Perhaps I am off base on this, but I would check and confirm that you are bringing the lossless WAV file into iTunes (if there is any conversion, which I thought there was) using an Applelossless codec versus the standard MP4.

Also, I suspect that the internal DAC is part of the issue, but it sounds like you are already planning on doing something about this.
audioengr
3,282 posts
 
The difference is jitter. The stock AE has very bad jitter compared to a decent CD player or even a computer playing a CD. A reclocker can bring the performance of the AE beyond that of a good transport or CD player. Most audiophiles that are getting stellar results from Squeezebox, Sonos and AE are using a reclocker after it.

If you dont understand jitter, then read these papers:
http://www.positive-feedback.com/Issue22/nugent.htm
http://www.positive-feedback.com/Issue14/spdif.htm

Steve N.
Empirical Audio
arm OP
2 posts
 
Thanks everyone for the responses.

Steve N, I think you answered my question and the whole issue should be moot once I get an outboard DAC.

Ckoffend, I'm using iTunes for wav file encoding. I had read about others having issues with their encoder so I thought I would put it out there.
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