Apple Soundtrack Pro 3 - Manual (Page 307)

What Is a Submix and How Do You Use It?
In Soundtrack Pro, you use a submix to combine (or “sum”) the audio from different tracks
and busses, and route the audio to physical outputs. The name of this feature implies its
purpose—to mix the audio signals of a subset of the tracks and busses in your project.
If you are using external audio hardware that supports multiple physical outputs, you
can have multiple submixes in your project and then choose the physical output to which
each submix routes its audio. By default, all tracks are routed to Submix 1, and Submix 1
is routed to the Stereo 1, 2 outputs. You can easily add more submixes, reroute audio,
and change the hardware output setting using the Output pop-up menu in each submix.
Basic Signal Routing in Soundtrack Pro
At a minimum, any audio that you edit in the Soundtrack Pro Timeline passes through
the following “mixer objects” on its way out to the physical audio outputs: a track, a
submix, and the Master bus.
1
Master bus
Hardware
output
Submix bus Track
Audio clip Effects Volume fader
Audio post-production projects typically include many tracks and submixes. The following
diagram shows the signal flow of multiple tracks to just one submix. While this is an
unlikely scenario, it illustrates the fact that you can route as many tracks to a submix as
you like. See
Example: Mixing a Project with Submixes for a typical example.
1
2
3
4
Tracks Submix bus
Stereo panner
Setting the Submixes for Tracks and Busses
To be included in a project, the audio signal of each track and each bus must be routed
to a submix. By default, in new multitrack projects, there is only one submix (Submix 1)
and all tracks are routed to Submix 1. You can add as many submixes as you like and
route as many signals from tracks and busses to those submixes as you want.
To create a more elaborate project (as described in Example: Mixing a Project with
Submixes ), you create additional submixes.
307 Chapter 12 Basic Mixing in Soundtrack Pro