Audio Output Export Settings
When you use the Export Audio to AIFF(s) command or the Export QuickTime Movie
command, two settings affect the number and grouping of exported audio channels:
 The number of audio output busses specified in the Audio Outputs tab of the
Sequence Settings window
 The option chosen in the Config pop-up menu in the Save dialog (Export Audio to
AIFF(s) command) or the Audio Outputs tab of the Sequence Settings window
(Export QuickTime movie command)