When more than one mic is used on a source, it's crucial to filter these options, choose the best source, or add two together. Scott advises on some methods to accomplish this task, including phase adjustment.
- This week I want to go over some helpful guidelines to choose and combine different mic sources in a dialogue scene. Now this can be for a narrative film or a documentary. In this case, we have a Boom mic and a Lav mic in a scene. Now nine times out of ten, I'm looking to simplify. The less sources you have, the better and more solid sounding your dialogue tracks will be. So when I start editing my dialogue, if there's more than one source, like we have a Lav and a Boom here, I'm going to want to filter out and keep the best stuff and get rid of anything that's not sounding so good.
Here's a checklist I go over when I'm choosing sources. First I ask the question, is one of the tracks, the Boom or the Lav, much better sounding than the other? If so, you can just keep that one. Let's take a listen in this scene. Here is the Boom track. - Mr. Dalton sent me to collect a design. Is it ready? - No. - Well. (sighs) 6 PM. - Okay, it sounds okay, it sounds a little distant, right? And here's the Lav track of the same performance.
- Mr. Dalton sent me to collect a design. Is it ready? I see. Well, 6 PM. - Okay, well it definitely sounds better. It's closer and has more fullness, but it has a lot of noise in it. So, the answer to this question is neither of them are better than one another. The next question then becomes, if yes, does it have adequate coverage? Well, the Boom has complete coverage and there's no noise in it, but it doesn't sound better, so we're going to want to use the Lav to cut in underneath the Boom to reinforce it, but we can't just lay them both in there since the Lav has the noise.
So the next question becomes, if no, can we combine the sources partially or totally? So we can't totally combine these sources, again, since the Lav has noise, but we can partially combine them and that's what we'd end up doing. We want to go in here and undercut the Lav to fill in just where he's speaking in the Boom track and get rid of all the unwanted noise. So I'm going to go ahead and make that edit. So I'm just going to go ahead and just carve out the Lav only where I need it and get rid of all the other noise. Now the trick when you do this is that you want to make sure you're fading in and you don't hear the Lav popping in, so you're going to use some cross fades and you're going to try to get in and out of these as seamlessly as possible.
Let me go ahead and do this to both of these, fading in using Command F. You can also just type the F key to get an automatic fade. And I want to listen to this one because I feel like there might be a little bit of noise still inside that clip. So here we go, listening to the Lav. - Well. - Yes, so we're going to need to get rid of this section as well. Okay, so what we end up with against the Boom, let's listen to them both at the same time. - Well, 6 PM.
- Okay, that's sounding a little better. The Lav is reinforcing what's missing in the Boom and we're combining the two. We're also getting rid of the inherent noise in the Lav track. Now that leads us to our last question of this checklist I go over and that is, are there phase or off axis issues? So phase issues occur anytime you have two mics. The sound is hitting the different mics at different times. So in this case, his voice is hitting the Lav before it's hitting the Boom. And when you combine those sources, you want to make sure they're in phase, which means that you want the wave forms to line up as well as they can.
Now if I zoom way in here, you can actually see the wave forms just as I said, the Lav wave forms are recurring, the peak of this wave form is occurring slightly before the peak of the Boom. Now to get the most out of combining these sources, you're going to want to go ahead and line these up. So what I usually do is use the Boom as the anchor point and I move the Lav up against it, so I'm just really looking to time align the peaks and you want to make sure, as you go down, that it stays consistent, 'cause remember, Booms can move and Lavs are going to be stationary to the actor.
But it looks like they are both stationary and I'm going to go ahead and do the same on this track, just looking at these wave forms, moving it down, making sure they're lining up there. And I'm going to do it on the last clip here too, as well. Again, it remained pretty much a consistent time difference, probably a couple of milliseconds and we're just going to line up, see that peak right there, with that peak. And what the result of that sonically is just a little bit more clear and a little bit more sounding dialogue. Here's the two together now that they're time aligned and edited.
- Well, 6 PM. - Okay, much better. So, by adhering to this checklist and these guidelines and carefully selecting your sources and combining them when necessary, you can get closer to the solid clarity you're looking for when you edit your dialogue track.