Apple Soundtrack Pro 3 - Manual (Page 451)

These settings are stored in the finished stream for use by the playback device. Leave
them at their default values unless you have a specific technical reason for changing
them. For more information, see
About Options in the Bitstream Pane .
AC-3 Bitstream
export options
7 Choose Preprocessing, then choose from the export options in the Preprocessing pane.
Preprocessing options are applied to the audio data before encoding. With the exception
of the Compression Preset setting, leave these settings at their default values unless you
have a specific technical reason for changing them. For more information, see
About
Options in the Preprocessing Pane .
AC-3 Preprocessing
export options
8 If you like, use the After Export pop-up menu to choose a post-export action.
For more information, see Using Post-Export Actions .
9 Enter a name for the exported file, then navigate to the location where you want to save
the file.
10 Click Export.
451 Chapter 20 Exporting Multitrack Projects