Compressor Guide — GP Tools

Threshold, ratio, attack, release, and knee recommendations by signal type. Control dynamics without killing tone.

Common mistakes

2–3 dB of gain reduction is working. 10 dB is fighting the mix.

Threshold set too low — compressor clamps everything, not just peaks. Raise threshold until you see 3–6 dB of reduction on loud transients only.
Attack too fast on guitar/drums — kills the transient attack that gives the instrument its punch and character. Let the pick attack or drum crack through before the compressor clamps.
Release too fast — compressor pumps in time with the signal. On drums, you hear it breathe. Set release to match the track tempo or longer.
Using mix bus compression to fix a bad mix — if you need more than 2–3 dB on the bus, the problem is in the stems. Fix the mix, then glue it.
One heavy compressor instead of two light ones — a 6:1 ratio at -18 dB sounds worse than two 3:1 stages in series. Serial compression sounds more natural on dynamic sources like vocals.

Ratio quick reference

Ratio controls how hard the compressor clamps after the threshold is crossed.

1.5:1–2:1

Gentle glue. Mix bus, mastering. Barely audible — adds density without squash.

3:1–4:1

General purpose. Vocals, guitar, bass. Controls dynamics while preserving tone.

6:1–8:1

Heavy limiting territory. High-gain sources or aggressive bass control.

10:1+

Brick-wall limiting. Peak protection only — anything higher is a limiter.