Compressor

A dynamics processor that reduces the difference between loud and quiet playing by reducing the level when it rises above a threshold, then making up the loss overall.

Controls usually include threshold, ratio, attack and release, plus a makeup gain; the ratio sets how hard the reduction is and the attack decides whether the first instant of a note survives. On guitar the effect is heard as a more even, sustained line with a firmer low-level detail, and sometimes as a percussive squash when the attack is fast. Overuse flattens the dynamics that make playing expressive, especially in the picking hand.

Example: a country player uses a compressor with a fast attack to get the snap of every note to arrive at the same level during a fast run.

Compressor

See also