Sync sound mono stereo issue

Question

I'm currently syncing sound for a short film on Premiere CC. I synced all the clips in the timeline and it all syncs and sounds great. But when I "merge clip" the clips audio in the bin changes. The sync is still perfect but the sound goes from stereo to mono and tracks are added. The audio on-set was recorded in two ways.
1) 1 track stereo L+R
2) 3 track mono
When I merge clips with the the 1 track stereo, it goes from being one track to two. And it's no longer L+R. Both tracks are centered. When I sync the 3 track mono it adds 6 additional tracks. the top track being the audio and the bottom two being empty. Then the 4th track has audio followed by two empty tracks. Then the 7th track has audio followed by two empty tracks. Why am I having this issue and how do I fix it?
Tom if you're here I could use your help. Thank you!
Dan

Answer 1

The issue comes from multi-channel .wav files.
I've worked on projects with multiple audio sources where the sound guy recording each one as discreet .wav files. So if you had two lavs and a boom for a particular shot, each take would generate three distinct .wav files. It took slightly longer to align on the timeline for syncing, but when I performed Merge with them, everything worked fine.
But on my current project I was working with a different sound recordist who would record those multiple sources into a single multi-channel .wav file. They were all recorded mono, but on some shots it would result in 6 different recorded mono tracks. Premiere displays those multiple mono tracks in their own separate tracks, already lined up on the timeline.
But when I merge this audio with picture, the resulting clip is crazy.
When the audio is synced and merged with picture into a clip, it exponentially adds blank tracks. Normally, during a merge, stereo tracks are split into two distinct mono tracks, one for each channel and mono tracks should remain the same. That is what is supposed to happen. But as we see here, an additional thing is going on that shouldn't happen.
Instead, with multi-track files, it treats ALL of the tracks as singular multi-channel tracks and tries to "split" them by creating additional empty tracks. But the most bizarre thing of all is that the number of dupes is equal to the total number if tracks. So for a shot with two lavs and a boom, there would be three tracks in the one clip. But Premiere is treating each of the three tracks as if each of them has three channels and creates three tracks for each of them; one with audio and two blank ones, for a total of nine tracks. For shots with three actors on lavs and with a boom, there are four tracks that are multiplied four times, giving me 16 tracks. I even have some takes where the five original mono tracks are turned into 25 tracks. Again, only five of them actually have audio in them and the rest are blank.
It's exponential. Had I been given an 8 track file, it would be turned into 64 tracks but 56 of them would be blank!
To make it even more fun, the real audio is spread out vertically on the timeline with the dummy tracks in between also equal to the number of real tracks. So a merged 4 track clip places the real audio on tracks 1, 6, 11, & 16, but audio from a merged clip with 5 tracks puts the audio on tracks 1, 7, 13, 19, & 25. So I can't just do a blanket "Modify Audio Channel" on everything and delete the dead tracks. It is all relative.
After the clips were borked up with the extra tracks, I went to Clip->Modify->Audio Channels and turned off all the empty channels, then saved a preset based on how many tracks there were. So in my footage bin I was able to organize by Audio Info and it listed the number of tracks it had. So I could put all of my 12 Mono Track clips together, highlight them all, then apply my "12 Mono" channel filter preset to all of them at once. Then I dragged them back to the timeline and they were fixed. Technically, those blank tracks probably still exist, but they are no longer visible.
And better yet, it doesn't put any vertical gaps between them. So if my audio was really on tracks 1, 6, 11, and 16 it places them on the timeline in tracks 1-4.
Now that I have the presets I can apply it to any further projects where I encounter this. It is still idiotic and obnoxious but not as catastrophic as I thought it was.