Compressor
DynamicscompressorLight CPU
Dynamics compressor with optional sidechain key. dB threshold.
What it does
Glue-bus / sidechain dynamics compressor.
Wraps daisysp::Compressor. Settings are baked at init. When the Sidechain port is wired, the gain envelope is keyed off that signal instead of the input.
Parameters
-
Threshold (dB)
thresholdThe level above which the compressor starts working, in dB below full scale — 0 is the loudest the codec can carry, so every useful value is negative. Peaks above it get pulled down by Ratio; anything quieter passes untouched. With Auto Makeup on this doubles as the loudness control, because the makeup gain is derived from this number.
-
Ratio (:1)
ratioHow hard the part above Threshold is squashed. At 4 it takes 4 dB of input over the threshold to move the output 1 dB. 1 is a bypass — the maths cancels and nothing is reduced. Past about 20 the distinction stops being audible and this is a limiter in all but name.
-
Attack (s)
attackSeconds for the gain reduction to arrive once a signal crosses the threshold. Short values catch the transient itself, which makes a source sound controlled but blunts its attack; longer values let the initial hit through before clamping down, which is where a compressed drum gets its punch.
-
Release (s)
releaseSeconds to let go again once the signal falls back under the threshold. Too short on sustained material and you hear the gain moving between notes as breathing or pumping; longer values ride the average level and stay out of the way.
-
Auto Makeup Gain
autoMakeupLets DaisySP restore the level that compression took away, derived from your settings as roughly half the theoretical loss and recomputed whenever Threshold or Ratio changes. It is a sensible starting point rather than a matched level. ⚠ While this is ticked the Makeup field below is not emitted at all.
-
Makeup (dB, manual)
makeupGain added after compression, in dB. ⚠ Used only when Auto Makeup is off — ticking that box zeroes the makeup gain and derives its own, and codegen does not emit this value at all.
Threshold/Ratio/Attack/Release are baked at init (their setters recompute coefficients, so they are not modulatable). Wire a Sidechain source to duck this signal from another (e.g. a kick ducking a pad). Auto Makeup compensates level automatically; turn it off to dial Makeup by hand.
Ports
In
-
Audio In
input -
Sidechain
key
Out
-
Audio Out
output
Audio Control
Inputs
- Audio In
- Signal to compress.
- Sidechain
- Optional key — when wired, drives the gain envelope.
Outputs
- Audio Out
- Compressed signal.
Rules and gotchas
- Threshold/Ratio/Attack/Release are init-time only (not CV).