Ratio (Compressor)
Definition
The amount of gain reduction applied by a compressor relative to how far a signal exceeds the threshold. A 4:1 ratio means that for every 4 dB above the threshold, only 1 dB passes through.
In Simple Terms
How much a compressor squeezes the sound that goes above the threshold. A 2:1 ratio is gentle—barely noticeable. An 8:1 ratio is aggressive—really clamping down. Higher ratios mean more obvious compression.
In Practice
A 2:1 ratio on a vocal provides gentle, transparent control; an 8:1 ratio on a drum bus delivers aggressive limiting that significantly shapes the character of the performance.