Multicam Audio Mixing Madness

Just getting to find my way around DR14.3 and having trouble with one thing. I am trying to set up a multicam with 2 MP4 tracks containing video and ‘stereo’ audio (only as backup) and another wave track that is just mono audio. I need to use the backup audio on one of the cameras during the beginning of the multicam clip and switch to the mono wave track a few minutes into the multicam clip. To do this I use keyframes at the transition point. I have been able to get this to work for playback in the multicam timeline edit and multicam Fairlight. The “Main” slider has on it exactly what I want to hear. But when I switch back to the main timeline I don’t hear the same thing coming from the multicam audo track. It is stuck on the DAR audio. I do get the audio from the wave track - later on where I turned it up - but not the backup audio that I need from one of the cameras at the beginning – regardless of which camera -1 or 2 - I want video from. Flattening makes no diff. I must be missing a step… I do have video only selected when switching between cameras instead of audio follows video.

I found post: https://forum.blackmagicdesign.com/viewtopic.php?f=21&t=65202&p=367578&hilit=multicam+audio+mix#p367578
And this one: https://forum.blackmagicdesign.com/viewtopic.php?f=21&t=70389&p=393376&hilit=multicam+audio+mix#p393376

With similar issues and no apparent (to me) resolution. I have tried what of those discussions that I understood to be relevant as well as searching for other means modes and methods to no avail.

Overall my needs are modest in terms of complexity. I am trying to put together 4K MP4 videos of talks 45 mins to 1 hour recorded from 2 cameras and 1 DAR. Of course having no backup audio would be foolish right? So my backup audio is in the camera MP4 stream. I Infer from what some have said that audio recorded 'in camera' is not functionally accessible when using multicam in DR14.3. I hope I have that wrong because DR seems to do what I need - 15 especially - If multicam issues can be worked out. I tried 15b6 and had issues with multicam and crashes due to out of graphics memory (I think). I hope that gets better too - needless to say. I want to use a number of the improvements in it.

Any help would be appreciated.

What I found works best is to create the multicam only with camera media. Manually sync separate audio files underneath the multicam in the timeline.

Thanks Jim,

I guess that would work well enough for me. I will try but that leaves me with one question. What is the most straightforward way to access backup audio in a camera audio track when I need it? It sounds like I would have to render out just the audio. That would mean another manual sync. Overall, not optimal but certainly manageable.

I need to be careful about this, but this might mean I need to revisit V15.6. I had all sorts of problems with Fairlight not saving changes in multicam as well as the timeline editor not saving - no warning, at least nothing on the screen long enough for an ordinary human to read! The biggest thing multicam does for me is easy angle switching and track video & DAR audio sync.

What is the most straightforward way to access backup audio in a camera audio track when I need it?

What I do is make sure the A camera has the 'backup' audio. When I Flatten the Multicam, by default it will show the audio from A1. That allows me to include that in the mix should it be needed.