Gain

Gain is the amount of amplification applied to a microphone's raw signal before it is converted to digital audio. Set too low, the recording will sound quiet and noisy once turned up in editing. Set too high, loud words or laughs can clip, creating a harsh distortion that cannot be fixed after the fact.

The usual method is to speak at normal recording volume while watching the interface's input meter, then adjust the gain knob until the loudest peaks sit safely below the red zone, typically leaving speech averaging around -18 to -12 dBFS with headroom for surprises like a laugh or a dropped pen.

Gain should be set per microphone and per person, since voices and mic distance vary. A dynamic mic close to the mouth generally needs more gain than a condenser further away. Checking gain at the start of every session, not just once when the studio is set up, catches problems before they end up baked into the recording, especially after moving furniture, swapping cables or changing who is sitting where.