Sidechain Compression Explained: How to Do the Pump Effect
⚡ Quick Answer
Sidechain compression lets one track control the compression of another. The classic application: route the kick drum into the sidechain input of a compressor on the bass track — the bass ducks every time the kick hits, creating space in the low end and the "pump" effect of dance music. Settings to start: ratio 8:1+, attack 1–5ms, release 100–200ms, threshold for 6–10dB GR on kick hits.
Sidechain compression is responsible for one of the most recognizable sounds in modern music: the rhythmic pumping of house, techno, and EDM tracks where the bass and pads breathe in and out with the kick drum. It's also one of the most practical mixing tools — used subtly in nearly every professional mix to create space and clarity without volume automation.
How Sidechain Compression Works
A standard compressor monitors the track it's placed on and reduces gain when that signal exceeds the threshold. Sidechain compression changes the monitoring source: instead of monitoring its own signal, the compressor monitors an external signal (the sidechain input) and triggers compression on the original track when the sidechain signal exceeds the threshold.
The result: the compressor activates based on the sidechain source, not based on what it's actually compressing. A compressor on the bass track with the kick drum as its sidechain source compresses the bass every time the kick hit exceeds the threshold — regardless of what the bass itself is doing. The bass ducks when the kick hits, returns to full volume in between.
This creates two simultaneous benefits: the kick drum has more sonic space in the low frequencies (because the bass briefly moves out of the way), and the rhythmic ducking creates the pump effect that drives dance music's forward energy.
Sidechain Compression Setup in Every Major DAW
Ableton Live
Ableton's built-in Compressor has dedicated sidechain routing:
1. Drag a Compressor onto the bass track (or whichever track you want to duck).
2. In the Compressor, click the small triangle icon at the lower left — this opens the sidechain panel.
3. Click the "Sidechain" button to enable external sidechain input.
4. In the "Audio From" dropdown, select the kick drum track.
5. Leave "Pre FX" selected in the second dropdown — this routes the kick's clean, unprocessed signal into the sidechain.
6. Set compressor parameters for your desired effect (settings below).
The kick drum track's audio does not need to be audible in the mix for sidechain routing to work — you can route a ghost kick channel (volume at -∞) specifically for sidechain triggering while the main kick plays through a different track.
FL Studio
FL Studio uses a different sidechain approach via the mixer's routing system:
1. In the Mixer, set up the kick drum on one channel and the bass on another.
2. On the compressor plugin on the bass channel, locate the sidechain input — most third-party compressors (FabFilter Pro-C 2, Waves SSL, etc.) support sidechain routing through FL Studio's send system.
3. On the kick channel, create a send to the bass channel at 0dB send level — check "Sidechain" in the send settings rather than routing to the main mix.
4. In the compressor on the bass channel, enable external sidechain and the kick's signal will trigger the compressor.
For FL Studio's native workflow, Fruity Peak Controller connected to the kick's amplitude envelope provides an alternative sidechain method — right-click the bass channel's volume knob, link to controller, and select the Peak Controller from the kick channel.
Logic Pro
Logic Pro handles sidechain routing through the plugin's sidechain dropdown:
1. Add a Compressor to the bass track (Logic's native Compressor or a third-party plugin).
2. In the Logic Compressor header, locate the "Sidechain" dropdown — it appears in the top right of the plugin window.
3. Select the kick drum's channel strip from the dropdown.
4. The kick's signal now triggers the compressor on the bass track.
Third-party compressors in Logic Pro access the sidechain through Logic's sidechain routing — the compressor plugin needs to have "Sidechain" as an option in its plugin format (most modern VSTs/AUs do).
Sidechain Compression Settings for the Classic Pump Effect
| Parameter | Subtle Ducking | Classic Pump Effect | Hard Pump (EDM) |
|---|---|---|---|
| Ratio | 4:1–6:1 | 8:1–12:1 | 20:1 or limiting |
| Attack | 5–10ms | 1–5ms | 0.1–1ms |
| Release | 50–100ms | 100–200ms | 200–400ms |
| Threshold | 2–4dB GR on kick | 6–10dB GR on kick | 10–20dB GR on kick |
| Effect | Tight, barely perceptible space | Clear rhythmic breathing | Obvious, intentional pump |
| Genre | Pop, R&B, any genre | House, techno, hip-hop | EDM, progressive house |
The release time is the most important parameter for shaping the character of the pump effect. Short release (50–100ms): the bass recovers quickly after each kick hit — tight, subtle, creates space without obvious rhythmic breathing. Long release (200–400ms): the bass takes longer to recover — creates the obvious swell-and-release that defines the classic EDM pump. Match the release time to the space between kick hits at your project tempo for the most musical results.
Creative Sidechain Compression Applications
Vocal-to-Music Ducking
One of the most practical mixing applications: sidechain the vocal into the compressor on the music/instrumental bus so that whenever the lead vocal is active, the supporting music and instruments duck slightly. The result: the vocal is automatically more audible without raising its level — everything else moves out of its way. Settings: ratio 4:1–6:1, attack 10–20ms (slightly slow to avoid ducking the attack of each word), release 100–300ms, 2–4dB GR.
Sidechain Reverb
Sidechain the dry vocal (or any instrument) into the compressor on its reverb return. The reverb ducks when the source plays and swells in between phrases. This prevents reverb from obscuring the attack of each word while allowing the reverb tail to bloom beautifully in the spaces. Particularly effective on drum reverb sends — the reverb breathes naturally between snare hits rather than accumulating and washing through the entire phrase.
Kick-to-Mix Bus
A subtle kick-to-mix-bus sidechain creates a gentle pulse through the entire mix on each kick hit — a sense that everything breathes together in time with the beat. Applied very lightly (1–2dB GR), this technique is nearly subliminal but contributes to the feeling of rhythmic energy and forward momentum. It's similar to what happens when music is mixed through a compressor with program-dependent release — the mix naturally breathes with the dynamics of the kick.
Ghost/Trigger Channel Sidechain
For more rhythmic control over sidechain pumping, create a ghost trigger channel — a separate MIDI channel playing a kick drum sample at the exact rhythm you want the sidechain to follow, but with the channel fader pulled to silence (-∞). Route this silent channel as the sidechain trigger. This allows the sidechain rhythm to be programmed precisely (different from the actual kick pattern) or to use a different transient character for triggering than the actual kick drum provides.
Frequently Asked Questions
What is sidechain compression?
A compressor on one track triggered by the signal from a different track (the sidechain source). The classic application: kick drum triggers compression on the bass track — the bass ducks every time the kick hits, creating space and the rhythmic pump effect. The sidechain source controls when compression activates, not the tracked signal itself.
How do I set up sidechain compression in Ableton Live?
Add Compressor to the bass track. Click the triangle (bottom left) to expand the sidechain section. Enable Sidechain. Set "Audio From" to the kick track. Adjust compressor settings — ratio 8:1+, attack 1–5ms, release 100–200ms, threshold for 6–10dB GR on kick hits. Done.
How do I set up sidechain compression in FL Studio?
Use a third-party compressor on the bass channel that supports sidechain, route the kick channel as a send with "Sidechain" checked instead of sending to the main mix, then enable external sidechain in the compressor. Alternatively, use a Fruity Peak Controller on the kick channel linked to the bass channel's volume knob.
How do I set up sidechain compression in Logic Pro?
Add a Compressor to the bass track. In the Logic Compressor header, find the Sidechain dropdown (top right). Select the kick drum's channel strip. The kick now triggers the bass compressor. Third-party AU/VST compressors access sidechain through Logic's standard sidechain routing system.
What is the pump effect in music?
The rhythmic volume modulation in electronic dance music where bass, synths, or the full mix breathes in and out with the kick drum. Created by sidechain compression — kick triggers heavy compression on the bass or mix bus, causing ducking with each hit and swelling in between. Creates forward momentum and groove.
What compressor settings for sidechain compression?
Classic kick-to-bass pump: ratio 8:1–20:1, attack 1–5ms, release 100–200ms for moderate pump (200–400ms for obvious EDM pump), threshold for 6–10dB GR on kick hits. The release time shapes the character most — shorter = subtle space, longer = obvious pump. Match to tempo for musical results.
Can I use sidechain compression on instruments other than bass?
Yes — sidechain is used on: kick-to-bass (classic), kick-to-mix-bus (full mix pulses), vocals-to-music (everything ducks for vocal clarity), pads-to-lead (chords duck for lead melody), reverb return-to-dry signal (reverb breathes between phrases). One of the most versatile mixing tools across genres.
What is the difference between sidechain compression and ducking?
Ducking is the effect; sidechain compression is the mechanism. Ducking = one signal getting quieter when another is present. Sidechain compression achieves ducking automatically through a compressor. The terms are often used interchangeably in music production. Volume automation and dedicated ducking plugins can also achieve ducking effects.
Practical Exercises
Create Your First Kick-Sidechain Pump
Open your DAW and create a new session with a kick drum loop and a bass synth or sample playing simultaneously. Insert a compressor plugin on the bass track. Route the kick drum track to the compressor's sidechain input (the exact method depends on your DAW). Set the compressor ratio to 8:1, attack to 2ms, release to 150ms, and lower the threshold until you see 6–8dB of gain reduction when the kick hits. Play back the session. You should hear the bass duck away each time the kick strikes, then swell back. Adjust the release time until the pump feels musical and on-beat. Record a short video clip of the waveform to confirm the sidechain is working.
Sidechain Pump with Frequency Control
Set up a kick and bass track as before, add a compressor to the bass with the kick as sidechain source. Decide whether your mix needs a transparent dip or an obvious pump effect — this choice determines your attack and release. For transparent mixing, use fast attack (1ms) and medium release (80ms). For obvious pump, use slower attack (5ms) and longer release (200ms). Experiment with both, then commit to one. Record a 16-bar loop of each setting side by side. Next, insert an EQ before the compressor on the bass track and cut 2dB around 100Hz to reduce how much the kick and bass overlap. A/B the results: does the EQ + sidechain combo create better low-end clarity than sidechain alone? Write down your findings.
Layered Sidechain Compression with Multiple Sources
Build a complete bass + pad section: layer a kick, a sub-bass, a mid-range bass synth, and a pad. Insert separate compressors on both the bass and pad tracks. Route the kick to the bass compressor sidechain (standard setup). Now route both the kick AND snare to the pad's compressor sidechain using your DAW's routing capabilities — this makes the pad duck on both kick and snare hits, enhancing rhythm. Use different ratio and release settings for each compressor: bass = 6:1 with 120ms release, pad = 4:1 with 200ms release. The goal: create layered rhythmic breathing that enhances groove without sounding mechanical. Record the result, then remove the snare from the pad's sidechain and compare. Did the dual-source sidechain enhance the overall pocket and energy?
Frequently Asked Questions
Standard compression monitors the track it's placed on and reduces gain when that signal exceeds the threshold. Sidechain compression changes the monitoring source to an external signal, so the compressor activates based on the sidechain source rather than its own track's signal. This allows one track (like a kick drum) to trigger compression on another track (like bass) without the bass's own volume affecting the compression.
Start with a compression ratio of 8:1 or higher, attack time of 1-5ms, release time of 100-200ms, and set the threshold so the kick drum hits create 6-10dB of gain reduction. These settings will create a noticeable rhythmic ducking effect that's typical of house and EDM music while remaining musically useful.
A ghost kick channel (with volume set to -∞) allows you to route a sidechain signal specifically for compression triggering without it being audible in the mix. This is useful when you want the sidechain detection to work independently from the actual kick drum sound you're using, giving you more control over the pump effect's timing and intensity.
When the kick drum's sidechain signal triggers compression on the bass track, the bass volume ducks during the kick hit. This rhythmic reduction creates sonic space in the low frequencies so the kick drum can punch through without competing with the bass, resulting in a clearer low-end mix.
Pre FX routes the sidechain input from before any effects plugins on the source track. This ensures the sidechain compression responds to the clean, unprocessed signal of the kick drum, rather than a version that has been filtered, distorted, or otherwise processed by effects.
No, the kick drum track's audio does not need to be audible or turned on for sidechain routing to function. The sidechain routing only needs the track to exist and have an audio signal being routed to the sidechain input of the compressor.
Sidechain compression is used subtly in nearly every professional mix to create space and clarity without relying on volume automation. Common applications include ducking vocals under dialogue in podcasts, reducing string sustain when drums hit, and controlling pad or pad-like instrument volume when bass notes play.
Drag a Compressor plugin onto the track you want to duck (such as the bass track). Once placed, you can then access the sidechain panel and configure which track will trigger the compression effect.