Apple Final Cut Pro 6 - Manual (Page 995)

210 Part I Audio Mixing
4 In the After Export pop-up menu, choose “Send files to Final Cut Pro sequence.”
5 Enter a name for the exported file and click Export.
Soundtrack Pro exports mixdown files from the multitrack project and adds them to a
Final Cut Pro XML file containing the original sequence. For your convenience, the
audio tracks from the original sequence are moved to other tracks and are muted.
In Final Cut Pro, the Import XML dialog appears.
6 Use the Destination pop-up menu to choose your original project, then click OK.
A copy of your original sequence (with the name you specified in step 5) appears in
the Browser.
7 Double-click the new sequence in the Browser to open it in the Timeline.
The sequence opens with the mixdown audio correctly synchronized to your clips in
the Timeline and the original audio tracks muted.
When you want to work on the project in Soundtrack Pro again, you can reopen it from
the Final Cut Pro Timeline.