Hi,
I’m importing a FLAC file to Audacity and then exporting it to WAV.
Then I repeat the exact same process (same setting, signed 16-bit PCM), and the 2 WAV files that are created are not equal.
I’m verifying this by mixing file1 with an inverted file2, and not getting a silence track (the peak amplitude of the mixed track is -66.7872dB).
To make sure this test is good I mixed file1 with an inverted version of itself; then I indeed got a silence track.
How come?
Audacity is not primarily a format converter, it’s an application for recording, editing and processing audio. Audacity’s default settings are set appropriately for recording, editing and processing audio.
Audacity can be used as a flac → wav converter, but for bit perfect results you need to change one of Audacity’s default preference settings:
In “Edit menu > Preferences > Quality”, set “Dither” to “None”.
For normal use of Audacity (recording / editing / processing), the Dither setting should be set to “Shaped” for best sound quality.
Thanks for the quick answer. I read about dithering as a result 
Totaly agreed!
If you guys are doing professional recording, on cubase, nuendo, pro tools or stuff, Audacity might not be the right tools recommanded for you.
I disagree. Why do you say that?