How to prevent microphone bleed
Microphone bleed occurs when two or more subjects’ voices are picked up not only by their microphone, but on others as well. This is noticeable when a loud-talking subject’s voice is heard on another microphone whose gain trim is higher than normal because they do not speak very loud. This will result in an unbalanced volume of the loud voice since it is being recorded on both channels. Solution: Good luck. Okay, you want more than that:
1. Ask the softer speaking talent to speak up, so the gain trim can be adjusted lower.
2. Ask the loud talker to speak softer.
3. If possible, separate the subjects from each other — this will reduce the close-proximity bleed.
4. The best way with two or more microphones, but requires more work than a one-person operation, is to mix the audio with the soft-voiced channel fader lower until they begin to talk, then the trim is raised to normal levels while they are speaking.
5. However, the absolute best way is to use a boom shotgun microphone for all dialogue; thus not creating the “doubling” effect.
Sometimes there is an advantage to microphone bleed. If one microphone develops a noise (clothing, static, etc) use the bleeding microphone to pick up the clean audio; be aware that now, both subjects are on the same recorded channel. Of course, I don’t recommend this method for general audio, but it does get you out of a jam when you can’t stop and reposition or replace the microphone.