Sidechain compression keyed to the kick creates progressive house's signature pumping bassline effect

The ‘pumping’ effect central to progressive house is achieved by routing the kick drum as a sidechain trigger into a compressor placed on the bassline (and often the full mix bus). Each kick triggers a fast gain reduction on the bass, which then recovers over the kick’s release period — typically with an extended release time that spans into the next beat. This creates a rhythmic breathing or ‘ducking’ that pulses with the kick, enhancing the kick’s perceived transient and locking the bass and kick together in the listener’s perception. The release time is critical: too short sounds choppy; too long creates sustained pumping. Additional percussion elements (claps, hats) are refined with track delay for humanisation, EQ for frequency management, and bus compression for cohesion.

Examples

Ableton Live: put a Compressor on the bass track, side-chain input from the kick return. Set attack ~0ms, release ~200ms, ratio 4:1. Trigger the kick at 126 BPM and adjust release until the pumping lands on the 16th note after the kick.

Assessment

Set up sidechain compression on a bass synth keyed to a kick. Sweep the release from 50ms to 500ms while the track plays and identify the release value that produces the most musical ‘pump’. Explain what’s happening spectrally during the compression cycle.