Audio Sync Drifts When Recording Podcast

jordank93183625  wrote I'm recording a 4 channel podcast using Adobe Audition and a Behringer interface. We started to film our podcasts and I've noticed that the audio we are recording in Audition falls out of sync with the video when editing in Premiere.  I've also noticed every so often there are very minor pop/clicks in the audio recording that seem coincide with the sync issues.

How have you synced the bit-clocks between whatever you're recording the video on and the Behringer? Okay, I admit that that was a loaded question, because you haven't - there's no word clock input on the Behringer, so you can't. What you need to understand here is that just because it's 'digital' that doesn't mean it's perfect - there is in fact quite a wide (in sync terms) clock tolerance allowed for audio and indeed video recording. The only way you can guarantee that two separate recording devices with their own clocks will stay in sync is if you designate one as being the master, and lock the other one to it. This is what professional kit allows you to do.

As for the pops - well this could easily be sync-related - it all depends on exactly how you've edited the results. What happens if you run two almost-synchronous sources together is that all the time the clock pulses are less than one pulse apart, it will sort-of work. The moment they get to the whole-pulse point - well that's when you get a pop.

There are no good solutions to this, other than the one I've already mentioned. Quite often, material can get a significant amount out of sync - the drift over an hour can easily get up to a couple of seconds with equipment like Behringer produce - and that's an error of only about 0.01% on the clock speed. The normal 'fix' involves either stretching or shrinking the audio to fit the video (which still doesn't take account of local drift), or simply re-syncing the audio when the drift gets to an unacceptable state.

There's loads of information about this if you do a search using a term like 'audio word clock sync'.