How to record the audio of one person's reaction to another person's line without overlapping audio?

Question

I was told that it was best to record audio separately for every talent so that it would be easier during audio post if I want to increase the gain for one of the tracks etc.

So if I only have a boom mic and I have a single shot of person A's reaction (no dialogue but some whispering) to person B's line, which will be fed to person A, how should I go about recording person A's reaction if I do not want person A's reaction sounds and person B's dialogue to overlap.

What I originally did was to focus on person A while person B feeds him his lines. But it resulted in person B's dialogue to be off axis and overlapped with person A's reaction sounds. And if I request person B to not feed the lines, how can I go about cueing person A on when to react? Thanks!

Answer 1

Would suggest these options:

• let B tell a shorter, "essence" version of a dialogue line. More like a call to action for A.
• queue the person from a distance, so the mic barely picks it up.

P.S.: I see numerous problems about dealing with 2 separate tracks that should sound coherent in the end. Among them: ambience differences, breath mismatches, frequency content disparity due to probable distance difference and yes, any dialogue overlaps like described. Skillful recording on a location would serve you well; making sure that a sound guy knows a dialogue would save you much more headache then an ability to have completely separate tracks. One track can be split into two (with care) and processed differently, provided you really need it. Otherwise, you end up with a need to construct a performance in an editing room, not with an option of doing so.

Answer 2

One (possibly overkill) option is to have each actor use a lavalier mic and record those to separate tracks.

This becomes much less feasible with more than a few actors at once.

You would also need a recording device capable of capturing separate tracks, and then you have the issue of properly exporting those tracks for post-production.

Answer 3

Another option is to use "overdubs" during post-production.

Your on-location recording will serve as a guide, and anything that needs more focus can be added afterwards.

The main drawback is that this method requires much more time, and of-course time is money.