EDUCATION
Compressor, see gain reduction happen
A compressor's threshold, ratio, attack and release are usually abstract numbers. Here they're a meter moving in real time, so you can see exactly when and how hard it grabs.
This is a free online compressor visualizer. Threshold, ratio, attack and release stop being numbers and become a meter you can watch: you see the exact moment the compressor grabs, how hard it pulls, and how long it takes to let go. Change one control at a time and the relationship between the four of them stops being theory.
Try it
- Lower the threshold until the gain reduction meter moves on every hit.
- Raise the ratio from 2:1 to 8:1 and watch the reduction get more aggressive at the same threshold.
- Set a fast attack, then a slow one, and compare how much of the transient survives.
What to listen for
A fast attack shaves off the transient, making a drum hit feel softer and rounder. A slow attack lets the transient through before the compressor engages, keeping the punch but still controlling the sustain.
Questions
What does threshold actually do?
It sets the level above which the compressor starts working. Below it, nothing happens at all. If your meter never moves, the threshold is above the loudest part of the signal.
Fast or slow attack on a kick?
A slow attack lets the transient through before the compressor reacts, which keeps the punch. A fast attack catches the transient itself and makes the kick rounder and smaller. Neither is correct; they are two different kicks.
How much gain reduction is too much?
Watch the meter rather than the number. If it never returns to zero between hits, the compressor is no longer shaping dynamics, it is holding the sound down permanently, and the result usually sounds tired.
What is the difference between a high ratio and a limiter?
Degree, not kind. A limiter is a compressor with a ratio so high that almost nothing passes above the threshold. Everything you learn here applies there too.
This tool is one part of the picture. Electronic Music Production for Beginners covers the rest.