Have you guys noticed compression on itunes/ipod?

[wefandango]

Did he specify what he meant by 'compression?' Because I definitely hear lossy data compression...

[DistortingJack]

I hear a graininess coming from iTunes compared to other apps (notably iZotope RX) which I attribute either to complete delusion or something to do with a lo-pass filter, but the feeling of compression from an ipod just comes from a shitty headphone amp, really ; )

[Realziment]

are saying as opposed to other mp3 format sites, or as opposed to cd?

[Joseph Schwartz]

I have A/B'd AIFF, AAC, 320k MP3, and 128k MP3 of the same songs in a control room and heard subtle differences among them.

Individually nulling out the left and right channels of AIFF and the other files produces substantial difference signals, i.e. compression artifacts.

[TwardyLikeTank]

Cheers dudes-of-sound, interesting replies.

He was talking about comparing the same file played in ProTools to the same file played in itunes.

[valis]

In what format though? Broadcast wav/aiff playback in both? Listening to the same mp3 or mp4/aac through both platforms? (which I don't think Protools can do btw without decoding the audio...)

[TwardyLikeTank]

Ohhh.... I don't know. What mysterious processes could be involved in different formats?

[valis]

Well comparing 48khz/24bit (or 44.khz/24bit etc) to 128-192k AAC (itunes compressed) is certainly going to show differences...