How to use Side Chain

How to use MultiTrack DAW
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How to use Side Chain

Post by pwnified »

Side Chaining is when a compressor uses a different input for the envelope follower inside the compressor. It's usually used to get a pumping or surging sound (ducking) when a bass drum or other transient sound hits.

AUv3's that support Sidechaining that I've tested:
Fabfilter: Pro MB, Timeless 3
Audio Damage, Inc.: RoughRider3
DDMF: NYCompressor
Blue Mangoo: Multiband Compressor
Bleass Compressor

First add a compressor plugin to a track or bus/master. If the plugin supports Sidechain, a button labeled 'SC' will appear just above the plugin icon:
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Tap this SC button, and a list of available tracks will pop up. A track can be sourced Pre or Post effects, the Post effects tracks are listed first. If a track is not available, it will be grayed out. Here we see that track 'Elec Piano' is unavailable because it is the track we are adding the sidechain to (sidechain cannot reference itself). Other reasons why a track might be unavailable (for Post Effects) is if it's a track that references this track as a sidechain source. This is to avoid circular references. Also, if a track is frozen, it will be unavailable as a Pre Effects sidechain source, but fine to use as a Post Effects source.
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The button will be lit up once you select the sidechain source:
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Then, you will have to enable the sidechain option in the AUv3, it will be different for each compressor UI, for example, Multiband Compressor has a button on the lower left:
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To get a really strong pumping sound, use a very short Attack time and very long Release time. Turn the Threshold down and Ratio up.
Sidechain source tracks should not be muted, as muting will stop the sidechain signal to the compressor. However, you can turn the Track Fader all the way down if you don't want the track to sound. The Track Fader is after the Pre and Post Effects taps in the signal chain, and only controls the volume to the final mix.