How can I get the audio track from the DAT to work on the nested sequence? It seems that the only audio I hear is that from Camera 1
That is correct, and the way to do it is to put the DAT on Audio 1. You'll have to do your mixing after the cut.
Once you're done cutting the multicam sequence, replace the cut audio track with the uncut original and do NOT enable multicam on the replaced audio. This will allow all original tracks to 'bleed through'. You can then do your mixing in the original sequence.
An alternative is to put Camera 3 on Video 1 track of the multicam source sequence (I think you're calling that your edit sequence). That is the only camera audio you want, right? Don't bother with the DAT track here (but mark any sync you have already set for the next step).
Nest this in the multicam enabled sequence and do the multicam cuts. Now add the dat track as audio track 2 in the multicam output sequence. Mix the audio there.
Jim, that is an intriguing method; is there an advantage?
It's nice to have the mix on the original sequence, that way anything I want to remove from the multicam sequence removes both video and mixed audio. Plus any audio adjustments required for the entire mix are easier applied.
See also my posting on the issue "Multicam is extrmely slow".
Make a timeline with all sources and sync them all, make sure everything is ok.
Then make a copy of this timeline and disable all video except one (for reference). Name it "Sound"
Move all soundtracks of your first timeline down to free soundtrack one.
Drag the sound track of "Sound" to track 1 of the first timeline. Then go on with the normal method for multicam (new timeline "Target", drag Source on it and enable multicam)
Any adjustmentsa needed in the sound can now be done in one place; Time line "Sound"
For performance reasons it might me better to drag the sound track of "Sound" directly to "Target" and disable soundtrack 1 (from Source). Disadvantage then is that removing parts from this multicam timeline needs the same removal from the soundtrack (on 2).
Hmmm, now I am writing this, can I unlink in Target the video and soundtrack and link soundtrack 2 to videotrack 1? Have to try that.