Apple Soundtrack Pro 3 - Manual (Page 265)

The Edit Channel dialog appears.
2 Drag the name of the channel to a different location in the channel list.
3 Click OK.
To add channels to an audio file
1 Choose Process > Edit Channels.
The Edit Channel dialog appears.
2 Click the Add Channel button.
3 Click OK.
To remove channels from an audio file
1 Choose Process > Edit Channels.
The Edit Channel dialog appears.
265 Chapter 9 Processing Audio Files