A feed-forward compressor with a soft knee, a hold stage and a tempo-synced release.
Inlets
Audio
2
Outlets
Audio
2
It measures the input, decides on a gain and applies it, so loud moments are turned down and the distance between loudest and quietest gets shorter. Detection is linked across channels: one gain is worked out and applied to every side, so a loud moment on the left cannot pull the image to the right. Set Threshold first, then CompressionRatio, then AttackTime and ReleaseTime, and MakeupGain last. On a part with a pulse, switch Sync on so the recovery lands on a division of the beat and stays there when the tempo changes. There is no key input; to compress one sound with another, use SideChain.
Parameters
InputGain
Trims the incoming sound before anything else. Raising it drives more of the sound over the threshold without moving the threshold.
MakeupGain
Gain added after the reduction, to bring the levelled sound back up.
AutoMakeupGain
Works the makeup gain out from Threshold and CompressionRatio, so changing either does not also change the level. Handy while dialling in.
AttackTime
How quickly it responds once the threshold is crossed, in milliseconds. Fast catches the hit; slow lets the hit through and levels what follows.
HoldTime
How long full reduction is kept before release begins, in milliseconds. Stops the compressor letting go and grabbing again on material that dips briefly.
ReleaseTime
How quickly it stops once the sound falls back below the threshold, in milliseconds. Ignored while Sync is on.
CompressionRatio
How firmly the sound is held. 2 means a sound 2 dB over the threshold ends up 1 dB over. Low ratios level, high ratios flatten.
Threshold
The level where compression starts. Above it the sound is held down, below it nothing happens.
KneeWidth
How gradually the ratio arrives, in dB either side of the threshold. A wide knee eases in instead of switching on.
Sync
Times the release to the transport instead of ReleaseTime. Attack stays where you put it.
SyncUnit
The note value the synced release counts in, such as 1/8.
SyncMultiplier
How many of that unit make one release.
Recipe
Drum bus glue
Threshold 0.4, CompressionRatio 3, KneeWidth 8, AttackTime 20, HoldTime 0, Sync on with SyncUnit 1/8. Cord a Mixer's drum sum in, switch AutoMakeupGain on while setting the threshold, then off once the level sits where you want it.
