Threshold and makeup gain are the two essential compressor controls; all others refine the action

A compressor requires only two controls to do its core job: (1) Threshold — the level above which the compressor starts reducing gain; (2) Makeup gain (or output gain) — restores the overall level that was reduced by compression. With just these two controls, the engineer can reduce dynamic range and maintain a useful mix level. All additional controls (ratio, attack, release, knee) refine how the compressor acts once it has engaged, affecting factors like how aggressively it clamps down, how quickly it responds to transients, and how the onset of gain reduction sounds. Beginning engineers should start with presets and focus on threshold/makeup gain before worrying about attack/release time settings.

Examples

Setting threshold at -20dBFS on a strummed guitar means all chord strums above that level get compressed; makeup gain at +6dB brings the average level back to where it was before compression — but the loud strums are now controlled.

Assessment

Explain the relationship between threshold and makeup gain in plain terms. Why is automatic gain compensation on a compressor a potential problem when using compression for mixing balance decisions?