Mix & Master
Sidechain Calculator
A sidechain pump only feels right when the ducking recovers in time with the track. Enter your BPM, pick how tight you want the pump, and get a release time that resolves on the grid.
From production experience the release math is universal; the per-genre timings are drawn from real studio use. · Methodology
Working out the release time
release (ms) = (60,000 ÷ BPM) × note fraction
One beat at 128 BPM is 60,000 ÷ 128 = 469 ms. An 1/8-note pump is half a beat, so the compressor should recover in about 234 ms, fully open again just before the next kick lands. Set the compressor (or volume-shaper) release to that value and the ducking locks to the groove instead of fighting it.
Getting the pump to breathe
The release is the control that matters. Too short and the pump sounds like a stutter; too long and the track never fully recovers between kicks, leaving everything sounding squashed and lifeless. Timing it to the beat is the difference between a pump that grooves and one that just sounds compressed.
A volume-shaper plugin with a drawn envelope gives you more precise control than a compressor, because you shape the exact curve rather than chasing attack and release knobs, but the timing target is identical either way. Whatever tool you use, high-pass the sidechain trigger so only the kick's low end opens the gate, not the whole mix.
Sidechaining everything to the kick, including the hats and top end. You only need to duck what's competing with the kick in the low-mids: the bass, the sub, big pads. Ducking a hi-hat just makes it sound nervous.