[mdisraeli]

320kbps with highest quality setting is pretty much an industry standard now, and many DJs, myself included, make use of that.

As you've looked into this before, do you know what the similar difference is like for such professional-grade encoding?

[joe_bleau]

(Note: no idea what mp3 encoder Audacity uses, and I'm sure the results will vary with encoder settings as well.)

I just fired up Audacity and generated a click track, with the first click at 1 second in. The exported 44.1k wav file, when loaded in Audacity, shows the click at exactly 44100 samples in.

The exported mp3 file, when loaded, shows the click to be around 46357 samples in. (It's a bit hard to measure, because the encoded has smeared the pulse.) Somewhere between 51-52 ms late relative to the wav file.

Listening to the wav and mp3 ticks summed, the delay is obvious--they are not in sync at all. Adding 2257 samples of silence to the front end of the wav file puts them back in audible sync.