Attack and release times on a sidechain compressor shape the ducked signal's envelope

On a sidechain compressor, attack and release control how the ducked signal sounds, not just how much it is reduced. A slow attack lets the initial transient of the compressed signal pass before gain reduction engages — useful for preserving a piano’s attack while still pumping its sustain. A fast release brings the compressed signal back up quickly between duck events for a lively pump. Too slow a release and the signal never fully recovers; too fast on a dense trigger pattern and you hear breathing. Threshold and ratio set the depth of ducking; attack and release set its shape.

Examples

Kick-to-piano: set attack slightly slow (~15–30 ms) so the piano transient sneaks through; set release quick enough (~100–200 ms) that the sustain returns between kicks. The waveform shows the piano dipping in sync with each kick hit.

Assessment

Given a sidechain setup where the piano sounds ‘clicked off’ then snaps back to full volume with no musical shape, identify which parameter needs adjustment and in which direction.