Sidechain

A sidechain lets an effect listen to a track other than the one it is sitting on. The classic case: the bass compressor listens to the kick, so the bass dips on every beat and the two never fight. The listened-to track is never heard through the effect; it only tells the effect when to act. Four effects offer it: Compressor, Gate, Delay and Reverb.

When to use it

Use the Compressor with a kick source to carve room for the low end, or with a vocal source to duck a pad under the singer. Use the Gate with a hi-hat source to chop a sustained chord into a rhythm. Use Delay and Reverb ducking to keep echoes and tails out of the way while a part plays and let them bloom in the gaps.

Controls

Source picker

Each of the four effects has a small cable icon in its header. Click it to choose the source: This track, or any eligible track in the project. A tint and a dot mark an external connection, and the icon stays available when the card is minimized. Audio tracks, instrument tracks, groups and return tracks can be sources; connections that would feed back on themselves are not offered. Names follow track renames, and a source that is later deleted is shown as missing and supplies silence rather than quietly switching back.

Compressor and Gate

The detector hears the source track after its effects, before its fader, pan and mute. Threshold, Attack, Release and the rest keep their meanings; the Threshold meter and the display’s detector lane follow the source, labelled Key when externally driven. A missing source lets a gate close through its normal hold and release.

Delay and Reverb ducking

Here the picker is labelled Ducking, with Off, This track and the other tracks. Choosing a source reveals a Ducking slider: at 50% the wet signal drops by up to 12 dB when the source is loud, and at 100% by up to 24 dB. Only the echoes or the reverb tail duck; the dry signal, the repeats and the tail itself keep their character. This track ducks the effect under the very part it is on, which is the usual vocal setting.

Solo, mute and timing

Soloing the target keeps its trigger working even though the source is silent in your speakers. Muting a source track silences it without breaking the connection. Latency between the two paths is aligned automatically, so a kick trigger lands exactly on the beat it came from.

Tips

• Start the ducked compressor with a fast Attack and a Release set so the bass has recovered before the next kick; the groove lives in the release.
• For Delay and Reverb, try This track first; an external source is for when a different part should clear the space.
• Portable chain presets drop song-specific connections, so reconnect the source after loading a preset into another project.