Apple Soundtrack Pro 2 - Manual (Page 409)

Chapter 16 Exporting Multitrack Projects 409
6 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.
 Compression Preset pop-up menu: Specifies one of the dynamic range processing
modes built in to the Dolby Digital Professional (AC-3) format. The default of Film
Standard Compression should only be used when you are encoding an original mix
intended for cinema. In almost all cases, you should choose None.
Important: It is critical that you have set the Audio tab’s Dialog Normalization setting
correctly if you intend to use any of these Compression Preset settings. The
Compression Preset settings assume that the audio, after the dialogue has been
normalized, is at the normal listening level of 31 dBFS. Levels that are consistently
louder than that result in distorted sound and erratic levels.
Note: If you are building a Dolby Digital Professional 5.1 channel surround sound
DVD, you will use Film Standard Compression.
AC-3 Preprocessing
export options
Choose a compression
setting from the
Compression Preset
pop-up menu.