You searched for sidechain compression settings because the tutorials all disagree: one says 2 dB of gain reduction, the next says slam it 10 dB. They contradict each other because sidechain compression does two completely different jobs, and most guides never say which one they are setting up. Settle that first and every knob has a clear target. This guide gives you exact numbers for both jobs, plus the release math for your BPM, in about ten minutes of work.
Sidechain compression has two jobs, and every setting depends on which one
Job one is transparent ducking. The kick and the bass want the same 40 to 100 Hz at the same moment, so you dip the bass a few dB for a few dozen milliseconds on every kick hit. Done right, nobody hears the compressor, only a kick that punches and a bass that never gets in its way.
Job two is audible pumping. You duck pads, bass, sometimes the whole music bus hard enough that the mix breathes around the kick. French house, melodic techno breakdowns, and half of modern EDM use that pump as a rhythmic element in its own right. Same tool, opposite goal, which is why every setting below comes in two versions.
Threshold and amount: 2 to 4 dB for transparent, 6 to 10 dB or more for the pump
Ignore the threshold value and watch the gain reduction meter; threshold only means something relative to the trigger level. For transparent ducking, lower the threshold until the meter shows 2 to 4 dB of gain reduction on each kick. That clears the low-end collision without an audible dip; if you can hear the bass duck when you solo it, you have gone past transparent.
For pumping, aim for 6 to 10 dB, and go past 12 dB on pads if the track calls for a heavy breathe. The pump only reads as intentional when it is obvious; a timid 4 dB pump is too loud to be invisible and too quiet to be a groove. Use a high ratio, 4:1 up to 10:1, so the reduction stays consistent instead of varying with kick velocity.
Attack: 0.1 to 1 ms, so the duck starts before the bass note lands
Set the attack between 0.1 and 1 ms. The compressor sits on the element being ducked, not on the kick, so a fast attack cannot eat your kick transient: the kick is only the trigger and passes through untouched. It pulls the bass down immediately, so the first 10 ms of the kick, the part that carries the punch, plays into clean space. At 10 ms or slower, bass leaks through right where the kick transient lives. If the compressor clicks at 0.1 ms, nudge it toward 1 to 3 ms or use lookahead.
Sidechain release time is the musical decision: time it to the gap
Release is where sidechain compression is won or lost: it decides how long until the bass is back. At 128 BPM a quarter note is 469 ms, an eighth is 234 ms, and a sixteenth is 117 ms. Those three numbers are your grid.
For transparent ducking, set the release between 60 and 120 ms. Most kicks spend their low energy within 100 to 150 ms, so the bass is back at full level long before the offbeat eighth at 234 ms and the groove keeps its drive. For pumping, stretch the release to 200 to 350 ms so the recovery sweeps across most of the beat: the breathing you hear in French house drops.
Then loop the drop and listen to the offbeat. If the bass note on the "and" sounds choked, the release is too long and the duck is swallowing your groove: shorten it in 20 ms steps. If the low end flutters between hits, it is releasing too fast: lengthen it. The right sidechain release time sits between those two failures, usually a window only 40 to 60 ms wide.
What to sidechain, and what to leave alone
The bass gets sidechained in every four-on-the-floor track, because kick and bass share the sub octave and one of them has to yield for those 80 to 120 ms. Who owns the sub in the first place is its own decision tree, covered in the guide on mixing kick and bass together; the settings on this page execute whichever choice you make there.
Pads, strings, and atmosphere take 2 to 6 dB even when you are not chasing an audible pump. Sustained sounds are exactly what masks a kick, and a gentle duck on the ambient bed opens a pocket on every hit that makes the drums feel louder for free. In house mixing and trance production that breathing bed is half of what makes the drops feel alive. Duck reverb and delay returns 3 to 6 dB too, triggered by the kick or by the dry signal feeding them, so the tails stay out of the way and bloom back in the gaps.
Leave the lead melody alone unless pumping is explicitly the aesthetic. The ear follows the melody and hears every dip in it long before it hears a dip in a pad, so a ducked lead sounds like a mistake. And if you are unsure whether your low end sits still or secretly pumps, upload a bounce to TrackSensei: it measures how your kick and bass energy moves over time against released tracks in your genre, a question your monitors keep dodging.
Use a ghost kick trigger so the pump survives the breakdown
If the real kick triggers the sidechain, the duck disappears the moment the kick drops out, and the bass and pads jump up while the groove deflates. The fix: duplicate the kick onto its own channel, keep it playing a straight 4/4 pattern through the whole track, route it to the sidechain input, and pull its output fader all the way down. The compressor still hears it, the listener never does, and the pump stays consistent through a 16-bar breakdown where the real kick is silent.
How to sidechain in Ableton: Compressor on the bass, kick as the input
To sidechain in Ableton you do not need a third-party plugin. Drop Ableton's Compressor onto the channel you want ducked, the bass or the pad, not the kick. Open the small triangle on the bottom left of the device to reveal the sidechain panel, switch on the Sidechain button, and set the Audio From dropdown to your kick channel. That is the whole routing: the kick triggers the Compressor, the Compressor pulls down the bass. This is the Ableton Compressor sidechain setup that every four-on-the-floor track runs on, and the numbers from this article drop straight into it.
Set the model to Peak so it reacts to the kick transient rather than its average level. Pull the threshold down until the gain reduction meter reads 2 to 4 dB on each kick for transparent ducking, or 6 to 10 dB for an audible pump, exactly the targets from the threshold section above. Set the ratio to 4:1 for a clean duck and up to 10:1 when you want the pump to stay consistent across kick velocities. Attack goes to its minimum, 0.1 to 1 ms, so the bass is already moving before the kick's punch lands. For release, type in the millisecond value the BPM math gives you: 60 to 120 ms for transparent ducking at 128 BPM, 200 to 350 ms when you want the breathing pump, then tune it against the offbeat test rather than trusting Ableton's tempo-sync button.
If you want the same routing for a heavier rhythmic pump rather than a clean low-end fix, the move is identical: the only thing that changes is how hard you push the threshold and how long you stretch the release. And if the kick drops out during a breakdown and the pump dies with it, use the ghost kick trigger above, route that silent duplicate into the same Audio From slot, and the duck survives the 16 bars where the real kick is gone. The same kick-versus-bass decision tree from mixing kick and bass together still decides who yields; Ableton's Compressor just executes it.
Frequency-selective ducking vs full-band: duck only where the kick lives
A normal compressor ducks the whole bass, top to bottom. A dynamic EQ or multiband compressor in sidechain mode ducks only the band you choose, typically 40 to 150 Hz, the only region where kick and bass genuinely fight. The mids and highs keep playing, so the bassline's character stays intact while the sub steps aside on every hit. That makes selective ducking the cleaner choice for melodic genres and any bassline whose midrange carries the hook. Full-band is the right call when the pump itself is the sound.
The three ducking mistakes that flatten a groove
First, syncing the release to a quarter note because the plugin offers a sync button. A quarter at 128 BPM is 469 ms, so the bass never reaches full level between kicks and the offbeat stays permanently half-swallowed. Sync is a starting point; the final value comes from the offbeat test.
Second, sidechaining everything. When bass, pads, leads, and FX all duck on every kick, the mix never sits still and the ear has no stable reference to measure the pump against. Duck the two or three elements that genuinely collide with the kick and leave the rest static; contrast is what reads as groove instead of seasickness.
Third, ducking the sub but not the mid bass. A bass patch carries harmonics from 100 to 400 Hz that mask the kick's body just as much as the sub masks its weight. If you only duck below 100 Hz and the kick still sounds buried, widen the ducked band up to 150 or 250 Hz, or add a small full-band duck on top.
Dial it in once, then let the analysis confirm it
That is the whole craft of how to sidechain: decide the job, set 2 to 4 or 6 to 10 dB of reduction, attack under 1 ms, release timed to the gap and tuned against the offbeat test, ghost trigger if the kick ever drops out. What you cannot fully judge in your own room is whether the result matches the records you compete with, because monitors and headphones disagree most in exactly the octave the sidechain controls. Upload your track for AI feedback and read the low-end and dynamics sections: they show whether your kick and bass trade places cleanly or smear together. You set the release by ear; the analysis tells you whether your ear was right.