What is Attack & Release Times?

Attack and release are the two most musically important controls on a compressor. The attack time determines how many milliseconds pass between the signal crossing the threshold and the compressor reaching its full gain reduction amount. A fast attack (0.1-1 ms) catches the initial transient almost immediately; a slow attack (20-50 ms) lets the transient pass through before the compressor engages. This single control determines whether a sound is punchy or smooth. Release time governs how quickly the compressor returns to unity gain (no compression) after the signal falls below the threshold. A fast release (50-100 ms) means the compressor resets quickly, preserving the natural dynamics of the source but potentially causing a "pumping" effect if it is too fast. A slow release (200-500 ms or more) means the compressor stays engaged longer, producing smoother, more sustained compression but potentially never fully resetting between hits. The interplay between attack and release creates the "character" of the compression. A slow attack with a fast release gives punchy, breathing compression that is ideal for drums. A fast attack with a slow release produces smooth, controlled dynamics that work well for bass and vocals that need to sit at a consistent level. Understanding these relationships is essential for using compression musically rather than mechanically.