The input level of a channel, set so each track hits the mixer at a consistent loudness.
Gain, sometimes called trim, controls how hot a track's signal enters a mixer channel before it reaches the fader. It sets the starting level so different tracks play at a comparable loudness.
Why it matters
Tracks are mastered at different volumes. Matching gain channel to channel keeps a mix even, so a quieter track does not vanish under a louder one mid-blend.
In practice
Set gain so the channel meters peak in the same range as the other deck, ideally with a little headroom before the red. Use your ears as well as the meters.
