What mic bleed actually is
Record two people in the same room and every open microphone picks up both voices, just with the "wrong" one at a lower level and slightly delayed. Mixed together, that delayed copy combs with the main signal and creates a thin, hollow, slightly phasey quality that's easy to hear even when you can't quite place what's wrong.
Why it's so hard to remove afterwards
Steady background noise, like hiss, hum or a fan, sits in a predictable, learnable frequency range that a processor can subtract cleanly. Bleed doesn't. It's another human voice, occupying the exact same frequency range as the voice you want to keep, arriving at a slightly different time. For most traditional tools there's no clean fingerprint to remove; anything aggressive enough to touch it will damage the primary voice too.
A little bleed is okay
A good pair of industry standard mics will always have a small amount of bleed, and it shouldn't be too noticeable once a well-adjusted noise gate is doing its job. Sometimes hearing and feeling the room in a podcast gives it a natural, unique character, so don't chase a sterile, perfectly isolated sound at the expense of the conversation's energy.
Fixing it at the source
- Increase the distance between speakers, or between each mic and the other person, however small the room allows.
- Use directional (cardioid) mics angled away from each other, so each capsule's rejection zone points at the other speaker.
- Check your mic settings and make sure they're set to any speech or voice mode they offer rather than a wide or music-oriented pickup.
- Have quieter mics off or muted when someone isn't actively speaking, rather than leaving every channel hot the whole session.
If it's already recorded
Light bleed in a well-treated room is usually less noticeable than people fear once the episode is balanced and mastered. Chasing it out with heavy manual processing tends to introduce worse artefacts than leaving it alone, so save that for genuinely bad cases and treat the rest as a lesson for the next session.
Optivox removes the bleed for you
Optivox analyses the sound of each speaker and singles out their voice, so you won't hear bleed on a processed file. Its noise reduction and speaker balancing smooth out the rest of the episode at the same time, and the master keeps the whole thing sounding consistent regardless.