What is sidechain compression?

Sidechain compression uses an external signal to trigger a compressor on a different track. When the sidechain signal is loud, the compressor ducks the target track.

The most common example: the kick drum sidechains into the bass. Every time the kick hits, the bass briefly ducks in volume. This creates space for the kick to punch through and gives electronic music its characteristic pumping feel.

How to set it up

The exact routing depends on your DAW, but the concept is the same everywhere.

• 1. Place a compressor on the track you want to duck (e.g., bass)
• 2. Set the sidechain input to the trigger track (e.g., kick)
• 3. Set a fast attack (1-5ms) so the compressor reacts instantly to the kick
• 4. Set release to match the tempo (shorter = more pumping, longer = smoother)
• 5. Adjust ratio and threshold until the ducking feels right in context

Sidechain for pumping vs. transparency

The pumping effect in house and EDM is intentional: slow release, high ratio, audible movement. This is a creative choice.

In rock and pop mixing, sidechain is used transparently: fast release, low ratio, just enough to prevent the bass and kick from fighting over the same space. The listener should not hear the ducking.

Other sidechain uses

• Ducking pads or synths under a lead vocal
• Triggering a volume envelope for a rhythmic gating effect
• Using a filtered sidechain signal (only the low end triggers the compressor)
• Multiband sidechain: ducking only the low frequencies of the bass when the kick hits