Compression & Dynamics
A compressor is an automatic volume knob. It turns down loud parts using the same envelope concepts from earlier lessons.
The Automatic Volume Knob
When a signal exceeds a threshold, a compressor reduces its level by a ratio. A 4:1 ratio means that for every 4 dB the signal goes above threshold, only 1 dB comes through. Simple concept, powerful effect. It tames peaks while leaving quiet passages alone.
Attack and Release
How fast the compressor reacts matters as much as how much it compresses. A fast attack catches the initial transient of a drum hit, good for controlling spikes, but it can make drums sound flat. A slow attack lets the initial punch through before clamping down, the same envelope concept as the ADSR from Parts 7–9, but applied to gain reduction instead of amplitude. Release controls how quickly gain returns to normal after the signal drops below threshold.
Makeup Gain
After compressing, the signal is quieter because the loud parts were turned down. Makeup gain brings the overall level back up. The result: loud parts are quieter and quiet parts are relatively louder, giving a more consistent, punchy level. This is why compressed drums sound "bigger": the sustain and room tone come up while the peaks stay controlled.
Try it: start the sequencer and watch the gain reduction meter. Try "Drum Punch" for a slow attack that lets transients through, then "Heavy Squash" to hear extreme compression flatten everything.