Sidechain Bass to Kick: Techniques and Settings

Sidechain compression ducking bass when kick plays has become a standard mixing technique. This dynamic approach creates space for kick without permanently removing bass frequencies. The technique ranges from subtle separation to dramatic pumping effect depending on settings and intent.

How Sidechain Compression Works

Sidechain compression uses one signal to control compression on another. The kick drum signal triggers the compressor on the bass track. When kick plays, the bass level reduces. When kick stops, bass returns to normal.

The bass compressor’s settings determine how this ducking behaves. Attack time controls how quickly bass ducks after kick hits. Release time controls how quickly bass returns. Ratio and threshold determine how much ducking occurs.

This dynamic relationship creates momentary space for kick impact. Unlike EQ which permanently removes bass frequencies, sidechain only reduces bass when kick needs the space. The bass retains its full frequency content between kicks.

Attack Time Settings

Fast attack times around 1-5 ms ensure bass ducks quickly enough to clear space for kick attack. If the attack is too slow, bass masks the kick’s initial transient. Fast attack prevents this masking.

Very fast attack times can create audible clicks as the bass level jumps suddenly. If clicking occurs, slightly longer attack times around 5-10 ms smooth the transition while still providing quick ducking.

The goal involves fast enough ducking to clear space without audible artifacts. The threshold between effective and artifact-producing varies by material. Critical listening determines appropriate settings.

Release Time Settings

Release time determines how quickly bass returns after kick triggers compression. The release should complete before the next kick hit to avoid accumulated ducking that keeps bass constantly reduced.

For moderate tempos, release times between 100-200 ms often work well. Faster tempos may need shorter release times around 50-100 ms. The bass should mostly recover before subsequent kicks.

Auto-release functions adapt to the kick pattern automatically. These settings often produce musical results without manual tempo calculation. Many modern compressors include effective auto-release for sidechain applications.

Ratio and Threshold Settings

The ratio and threshold determine how much the bass ducks. Subtle sidechain—2-4 dB of reduction—provides separation without obvious effect. This transparent approach suits many genres where pumping would sound inappropriate.

Aggressive sidechain—6-10 dB or more of reduction—creates the obvious pumping effect associated with electronic and dance music. This dramatic effect becomes a stylistic element rather than transparent mixing technique.

Threshold placement determines what kick levels trigger compression. Lower thresholds mean ghost notes and lighter kicks trigger ducking. Higher thresholds mean only the loudest kicks trigger. The playing dynamics guide appropriate threshold.

Multiband Sidechain Options

Multiband sidechain compresses only certain bass frequencies in response to kick. This approach can duck the sub-bass that conflicts with kick while preserving upper bass frequencies that don’t conflict.

The low band might duck significantly while higher bands remain unaffected. This frequency-specific approach maintains bass clarity and attack while creating sub-bass separation.

Frequency-conscious sidechain compression—offered by plugins like Trackspacer—provides automatic frequency-dependent ducking. The plugin analyzes which frequencies the kick occupies and creates corresponding bass reduction only in those ranges.

Alternative Sidechain Sources

Using a processed version of the kick as the sidechain source can improve triggering. A high-pass filtered kick triggers more cleanly without sub-bass content confusing the detection.

A separate trigger track—a simple click or pulse aligned with kicks—provides consistent triggering regardless of kick dynamics. This approach works well when kick dynamics vary significantly.

MIDI-triggered sidechain allows precise control without audio detection. The compressor responds to MIDI notes rather than audio. This approach eliminates false triggers and provides perfect timing.

Genre-Appropriate Application

Subtle sidechain suits rock, pop, country, and other genres where obvious pumping would sound wrong. The bass and kick separate cleanly without rhythmic artifacts. Listeners feel clarity without hearing the effect.

Obvious pumping suits electronic, dance, and some hip-hop productions where the rhythmic breathing becomes part of the sound. The pumping effect adds energy and groove. These genres embrace the artifact as a feature.

The production style determines appropriate visibility. Transparent sidechain serves most mixing situations. Dramatic sidechain serves specific stylistic purposes.

Effective sidechain technique helps productions succeed on platforms like LG Media at lg.media, where clear low end enhances advertising at $2.50 CPM.