Do you ever mix your channels using different mic's from the production sound?

Like for example: there is a line saying "Hey whats that" and it is recorded on both a boom and lav into the same recorder, do you ever mix both of these channels together or only use one of them?


As I understand it, these days it is common practice for production sound when recording multitrack to provide a mix on channel 1 (which is what the AVID editor uses) and then split each mic to seperate channels on tracks 2-8 (which is what the dialogue editor uses)

The mix on channel 1 is important as that is what is heard in rushes and therefore what the recordists work is judged by in the short term...


Mixing the different elements together to a dedicated mix track should be chosen if it's absolutely needed, in order to create a natural feel in the sound of the production mix track. As mentioned by Utopia (If it sounds good, it's good) and Morten, your production sound mixer usually has a number of dedicated record tracks to accommodate the various mic elements on set during a particular scene, e.g.:

Track 1: Mix

Track 2: Boom (Isolated)

Track 3: Wire 1 (Isolated; Usually named by character)

Track 4: Wire 2 (Isolated; Usually named by character)

Track 5: Plant 1 (Isolated)

Track 6: Etc...

There may be differences between how production sound mixers will create their track workflow, dependent on whether they have first and second boom, the amount of wires placed on cast, and also whether they have plant mics arranged around a set during a scene. Most often the boom will have precedence in the mix, leaving any wires or plant mics routed only to the iso tracks and not mixed into the dedicated mix track. But there are times when a wire (Lav) will need to be mixed into the dedicated mix track due to the nature of a scene.

For example, you may have a scene in which an actor is leaning forward and talking, the whole time, facing his/her feet, and the frame line is 4 feet above their head. The Shotgun mic on the end of the boom pole can only do so much to dig out the sweet spot of the actors voice when the closest they can get to the action is 6 inches above the frame line, which is 4 feet above the actor's head. That's 4 and 1/2 feet above the sweet spot, and sometimes the boom op is dodging a shadow falling just beside the actors shoulder caused by a light sitting just above the shot. In this case the wire will play (just enough to get the clarity of the voice), along with the boom in the dedicated mix track. The idea would be to have the boom play most of the mix, while adding the wire into the mix at a lower level, but just enough to have the articulation of the dialogue pop in the mix, while keeping the timbre of the dialogue sounding as it would when only carried by the boom. This can be difficult because wires don't usually sound as good as a shotgun mic (boom). That's where using great lavs (Sanken COS-11, Countryman B6) and using good mic placement pays off. Wires can sound very good, when placed well on an actor.

What most mixers do (as well as what I do) is have my boom op and utility talk into the wires individually along side the shotgun mic to check the phase between the mic signals being added to the mix track before they go out on set. I try to do this early in the beginning of the day, testing phase for all my wires between the shotgun, so I know that my phase assignments are set well just in case I need to mix the mic signals together on the mix track. Sometimes a certain mic will be placed on a different transmitter and I'll have to check phase again, no problem, I just have the boom op hold the shotgun mic over an actor and ask the actor to say a few lines and I adjust phase. When out of phase, the sound of the mix track will get thin, with the two mic signal causing a certain amount of cancellation. When in phase the sound of the mix track will be strong and robust, because the two signals will sum together with an additive effect. Even then, you mix in the separate elements only when needed, in order to properly support the essence of the picture on screen. You want it to sound so natural that the viewer believes what they're hearing, without knowing they are hearing the scene.

Three years ago I mixed a feature set in a prison. We had everything from fights to court scenes, intimate scenes between actors speaking into telephone hand sets in visiting booths with glass between them, as well as heavy dialogue scenes in real prison cells where the actors had their shirts off. We did everything from micing the perimeter walls of an outside yard set for wide shots featuring shirtless dialogue scenes, to placing a small shotgun mic on a small Arri 35 mini handheld film camera for fast moving fight scenes, to placing a Sanken Cub-01 on the bottom of a matt box for scenes in a real prison cell measuring 9ft x 4ft where camera was making numerous 360 degree turns following a shirtless actor (fortunately) speaking the whole time in front of the camera lens. During some scenes in this prison cell I was able to tape Sanken COS-11 Lav mics to the back walls near the actors as they delivered lines shirtless, while mixing in the boom (which could only come a couple feet into the cell because of a wide frame) to add body to the mix. The lavs played most of the scene while the boom applied a sense of space to the scene. You get the picture...

If it sounds good, it's good (great quote Utopia). The only issue I've had has been listening to films I've mixed after they release. The few films I've mixed have come out on DVD and I can always hear either my mistakes, or missing elements from my original production mix track. You always remember what you mixed for a scene, and sometimes you can tell when only one out of the few elements you mixed into the dedicated mix track is playing. It throws the whole scene out of whack in your head because you're expecting what you mixed, and you only hear the boom, or the wire, etc. Most people don't hear it, just you. So you have to say, well, as long as the pay check was on time and had all the right digits. The fun part is when you hear your work and the scene is so good that you get transported into the reality of it all, you forget you're watching a movie and you just enjoy the experience. It's what keeps us going back for more.

I love making sound for movies!

  • Great answer. Is the movie you're referring to named "Felon"? If so, a good friend of mine was in it.
    – Utopia
    Mar 3 '11 at 0:22

Per the interview done on the production mixer for King's Speech, he did do a bit of mixing of the 2 mics (boom and lav and sometimes spot mic and lav).

Personally, I use booms only and rarely use the lav unless that is the only choice or the boom is distorted of off-mic.

It's a personal preference. I think some mixers like having a chesty lav mixed with a boom to sort of even out the proximity.

That's for the mix. While recording the dialogue on the set, I ALWAYS keep both mics separate and NEVER commit a mix of the two mics to a recorder (unless there is absolutely no possible way to do so due to lack of adequate recorder inputs). This is so they can be separated later on while mixing if needed. There is, however, sometimes a mix that gets bussed together for the picture editor to work with (which is sort of like a temp mixdown of the dialogue mics onto a stereo or mono track) and this usually doesn't get used in the final mix.

There is definitely no hard rule that says you must do either method. If it sounds good, it's good.

  • Why do you use booms only and rarely lavs if lavs consistently give that intimate feel?
    – Chris
    Mar 2 '11 at 4:37
  • @Chris. Yes. I have yet to hear a good lav recording that I would want to mix over an on-axis boom mic - that's just my opinion and might be because I have never received a good lav recording - hence my lav mounting question.
    – Utopia
    Mar 2 '11 at 4:48
  • Has anybody ever swallowed a lav?
    – Chris
    Mar 2 '11 at 4:52
  • or any animals like an elephant or a lav tied to a rock and dropped in the ocean..
    – Chris
    Mar 2 '11 at 5:03

When I record production sound, I record all the microphones on separate tracks as well as a 2 track mixdown with the boom on one track and a mix of the lavs on the other track. This two track mixdown is for rushes and also for the editor. The editor gets the separate tracks as well, as there may be times, when the editor wants to get to the individual tracks. Everything of course also goes the sound editing.

I never mix the boom and the lavs together on one track and I never deliver just a mono track to the editors. All the editors I know hate mono mixdowns, as the mono mixes you make while on set are mostly of too poor quality for them to use. So when they get mono mixes, they always have to use the separate tracks, which slows down their editing quite a lot, and then they get pissed at the recordist...

So my normal track layout would be:

A stereo file containing:

Track 1: Boom Track 2: Mixdown of lav mics

A multitrack fil containing:

Track 1: Boom Track 2-8 or 2-10: Separate lav mics, placed mics, ambient MS mics or whatever.

The Sounddevices 788 and all of the Deva's can generate these two files simultaneously while recording.

If there is no boom mic in the scene, I might send some lav mics to track 1 and some to track 2 of the stereo file, just to give the editors some freedom while editing.


From a Post Production standpoint... it depends... :)

For example in one show I do, there are multiple radio's plus a boom. In a case where a character is far across the room, for example, he's be radio'd. But depending on the perspective of the shot, I might mix a bit of the boom in to get the natural room 'verb. I'll often do this for characters walking into a shot, IF the line can be treated as such. Sometimes story requirements require the line to be crystal clear. Usually I use both channels when the boom is just too far away, but the radio sounds too "dry". A combination of the two can be useful then.

On the other hand, if both are close enough, or it's a situation where one character is lav'd and the other is boomed, and both are being picked up by both. I'll pick the one best track to avoid phasing issues.


Hi, i work in Mumbai, India. Here most of the mixers don't mix the tracks. we record separate tracks, and then they go to the editor. they sync the tracks with video. Here most of times, all the actors in a scene are having lapel mics on them, besides the 1 or 2 booms. in the post production, we use the boom and the lapel tracks of the artist together to make his tone, i.e, at any time when somebody speaks, his/her lapel and the boom would be used for that. phase cancellations are usually taken care in the location it self. in my experience, there is no need to mix down to a mono.

the basic tracking will be like

1track. boom 1

2track. boom 2

3track. artist 1 lapel

4track. artist 2 lapel


usually the last 2 tracks (of a 8 track recoredr like Deva),

7 &8 are assigned for stereo ambiences, if possible.


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.