Apple Soundtrack Pro 3 - Manual (Page 316)

Using the Mixer
While most mixing tasks can be accomplished in the Timeline and elsewhere in the
Soundtrack Pro interface, the Mixer offers an interface analogous to hardware mixing
consoles found in most audio post-production facilities. Another advantage of the Mixer
is that you can view levels on all (or at least many) tracks simultaneously in real time.
The Mixer features a series of vertically arranged controls called channel strips, like the
channel strips in a hardware mixing console. The channel strips in the Mixer correspond
to the horizontal tracks, busses, and submixes in the project Timeline.
Channel strip
The controls a channel strip contains depend on whether it is a track, bus, or submix
channel strip. The controls for each type are as follows:
316 Chapter 12 Basic Mixing in Soundtrack Pro