03.04 Clean Up and Level Sounds

Single Band Compressor

A single band compressor can change the dynamic range or an audio file. These general rules of thumb apply to using a single band compressor for cleaning up foley sound effects.

To bring out hidden or quiet details in the recording such as footsteps, whispers, and background textures, use a Fast Attack (1–5 ms) and a Fast Release (30–60 ms). The fast attack make the compressor react the second the threshold is present so loud sounds are pulled down and the quieter sounds can be heard. The fast release allows the compressor to quickly start evaluating the next threshold and attach. Lower your threshold until the quiet parts of the recording get louder and pull the background audio details forward in the audio.

To preserve impacts such as explosions, gunshots, punches, and door slams, use a Slow Attack (20–30 ms) to let the initial “crack” or transient pass through relatively uncompressed. This allows the sound to stay big for a bit before getting leveled out so there is more dynamic range in the hit. Also use a Fast Release (40–70 ms) so the compressor has enough time for the next boom or bang sound.