phasing effect when mixing boom with lavalier mic

I ve got interviews to clean up with a bright echoey and noisy boom mic signal and a dry, muffled slightly, boomy but with good SNR lavalier mic signal. When i mix them together i can hear a bit of phasing effect. When i apply some Eq on the track with the lavalier mic i get slight more phasing effect as one is slightly delayed i guess due to the process…

Is there a way to overcome this? I.e. nudge each track few ms to correct the phase issues? Or do i have to choose one of the channels?

Since there are distance differences between the mouth-to-lav and the mouth-to-boom mic there will be timing differences. These timing differences are going to cause phasing when summing the two mics.

This can be be extrememly diffiuclt to correct and I spent hours dealing with this on a recent post-production spot.

The problem is the talents head might be moving around and the boom op might not be steady. This means the mics are picking up a sound that is constantly moving and therefor changing the phase relationship between the 2 mics.

I actually had to go word by word to correct this issue and it can be very time consuming… good luck!

thanks Chris, how exactly did you do it? automating a delay or something?

Come on…
you must have knowledge about how sound travels thru air and how it takes time.
You must edit all the phasing errors away as it is a matter of delay and nothing else. Sometimes you must sync every word (or even parts of words) to avoid phasing.
Or you can use either boom or lavalier, not both at the same time…

Bye / Tumppi

yeah i know all that, i just thought there might be a better way to do it, like a plugin or something…

You could try Vocalign. Not sure if it will introduce artifacts.

interesting, thanks Tom.

I just hand edit them.
I also then do clip gain adjustments at the same time so at least when I"m done the vo is all tidy and leveled and hits they dynamics processors later in the chain very consistently. Heck, by doing clip gain, I often don’t need much compression at all.

Might be a long shot but you could try

If there is little $ involved I’d probably go with one or the other, rather than spend time trying to blend the two. Time is money so I’d rather not burn too much on it on something like that. I’m sure there’ll be plenty of other work to do anyways. But I guess it also depends on the project. If it’s for TV, say a cooking show or reality show maybe, then who cares (honestly). If it’s a feature film then yeah, I’d be more inclined to “give” a bit more.

As for actually using both simultaneously, I’d say editing is your friend. You can’t really automate a delay because as the actors move they may change the distance to the boom, but the lav remains the same distance. Hence a different delay. If you have two actors and leave both lav mics up you can end up with a similar problem actually (the lav on Actor A always being the same distance to him, but different to Actor B) but at least it’s only 2 mics instead of 3.

But yes, time consuming… very time consuming. No way around it really.

Why on earth would you want to blend both?
Impossible that you ever get this right.

You will have to choose one of both. Sure, you can switch every few seconds from one mic to another (so to speak) or even have one actor on Lav and the other on boom, but don’t mix both together.


I’ve actually heard of people mixing both for reasons of tonal quality. Seems like a nightmare to me. But to each his own I suppose.

I don’t like to work with both. But on some projects, producers or the client already have some dialogue cut that way and I’ve had to continue it. Or they just demand it… so you have to work within the client requests.

I also prefer to pick one or the other, especially if they are trying to fly in post production dialogue… thats a nightmare to match sometimes…

I’ve mixed both together quite often.
I work like this:

  1. I always start by using Boom channel.
  2. If Boom is not good enough by itself I add a bit of lavalier to it (after editing it to absolute sync with boom track).
  3. If that does not work properly I use first the lavalier and add a bit of boom to make it fit better with other material
  4. If that don’t work I use only lavalier

Why like this you might ask?
Just because I generally hate the sound of lavalier mics and there is too often too many problems with lavalier mics. Clothes sounds etc…

Bye / Tumppi