Compressor

A compressor is a device or module that reduces the dynamic range of an audio signal by turning down its louder parts. Makeup gain can then raise the overall level, so the quieter parts end up relatively louder. You set a threshold where the compressor starts to act and a ratio that decides how much the signal above the threshold is reduced. Compressors make volume more consistent, increase sustain, and control peaks, which helps avoid clipping. They are used in both live sound and studio recording.