Roundtable Audio sub-frame Syncing Issue

[Jamesuk1981]

Hello

I am cutting a lot of roundtable discussions, each with 5x audio tracks from the speakers' lapel mics. I am able to sync the audio first at frame level by Audio Syncing, and then at sub-frame level by checking  "Show Audio Time Units" and manually mathing the modulations.  Inevitably without the sub-frame syncing, the audio isn't perfectly in sync and so I have a lot of reverb / doubled sounds from the different mics.

My biggest issue is that if I do my sub-frame audio edit to sync my clips, the moment I move the clips forward or back on the timeline using the "Track Select Forward" tool - for example, to add in new clips - the sub-frame syncing is lost, and the sync goes back to frame level, and the audio sounds reverby again.  This is a real hassle as I will have to go through all my audio edits again, to sub-frame sync, before I do final exports of the videos.

Is this something that can be worked around? Does anyone have tips on handling this? I assume this is a bug rather than a feature, and perhaps I should be exporting the audio out to Audition to do my subframe syncing - but it is annoying as there is no other reason to export audio to another app for this project.

Thanks

James

[RobShultz]

Is this a multicamera project? If so you could try setting it up as multicam and then change the setting to multicam audio follows video.

[Michael Grenadier]

yeah, this is an issue in this digital age...  Used to be you used "genlocked" cameras and recorders so that everything lined up perfectly.  Gotta say, don't really think  anyone's gonna see things out of synch be much less than a frame.  Back in the day working in 16mm, you could only adjust audio by a frame...  And you really had to use your judgement as to how the synch looked...  Not sure exactly what's happening when you adjust things in the timeline...  

I recently edited a piece with one person, shot with 2 cameras.  There were times where I wanted to use audio from both cameras (one camera had a feed from a lavalier) and yeah, it was not simple and although it sounded ok from within premiere, when I exported suddenly there were phase issues...  

But here's how I would proceed to deal with the out of phase issue which causes the reverb issue.  put each individual's audio on it's own track and then when you lock picture, you can clean up the "off mic" audio.  sounds like a pain but shouldn't be too time-consuming.   

[Phillip Harvey]

Maybe this is just my experience with things, what I've learned/heard over the years, etc. But you're always going to have a big chance of phase issues if you're trying to play multiple tracks simultaneously. I personally would not be going down the path of trying to line up the audio perfectly so that you can try to play 5 tracks at once. I don't even do that for 2 tracks at once. You can try Rob's suggestion of audio follows video with a MC sequence. I've also just gone ahead and done the work of manually cutting between the active audio channels. Way cleaner end result.

[Michael Grenadier]

and of course it can get complicated if people speak over each other...  but in that case, manually adjusting an audio clip on the subframe level AFTER you lock picture will solve that problem....  but as I said, you really need to do a test output and check that to make sure there's no subtle out of phase issues that are not evident in Premiere...

[Jamesuk1981]

Hi Philip, and the rest.
Thanks for the input.

Whilst my intention is to only have one active audio track at any time if possible, the issue I have is that there is a lot of overlapping dialogue. Including lots of "mmmm" and "aahh" as people talk. So I need to dip into these or they sound "off mic".  The issue, indeed, is a phasing issue.  And unless they are sub-frame synced precisely, then when I dip into other people making sounds, or speaking over the main speaker, other peoples noises or words sounds reverby and unsynced unless I do a sub-frame line up.  There wouldnt really be an issue if the sub-frame synce wasnt lost everytime I moved clips along time timeline.  It is a very odd thing. 

I do wonder how in studio enviroments on live tv, why there doesnt seem to be an issue with people's lav mics picking up the sound of other panellists audio.  I have attemped gating the tracks, so they kick in only when the people on-mic are speaking, but as they are all sat so close together, I can't seem to get the gating to work well enough to only open when the relevant person speaks.

I think I will just need to edit it with slightly out of sync audio until picture lock and then line up perfectly before mastering out the final videos. 

[Phillip Harvey]

Ah, makes sense. Yeah I don't have experience with those types of live environments, but I do have a broadcast prodcuer on my team at work. I'll chat with him to see what he does. I'm pretty sure those mics are heavily gated during the productions. I've received content from them before and coming from more of a standard production and post-production background I really disliked the obvious gating in the audio. I'd prefer consistency instead so that I can clean it up later. But it's not quite the situation that you're in. I have cut together some round-table stuff before with like 6 people and I'm pretty sure I just approached it manually at the time. But if it was something I was going to do a lot of I would likely aim to streamline the process.

[Michael Grenadier]

In a professional studio environment the cameras are usually routed thru a switcher and the audio is always recorded 'in phase.'  but what's considered professional nowadays isn't the same as when I was often in this sort of environment...    and yup, editing slightly out of phase and fixing it when you lock picture is the way to go..