Upon first impression, a compressor's functionality can appear mysterious, and reaching the desired effect can prove elusive without knowing the compressor's basic properties. Used properly, compression can add clarity, punch, and power to sounds, songs, and mixes. Used poorly, compression can kill the presence and vibrancy of a track.
Compressors even out dynamics
At the most basic level, the function of a compressor is to even out a dynamic signal. Compression takes the exceedingly loud parts of an audio signal and makes them softer. Once the louder segments have been brought down, the overall volume of the audio can be raised, resulting in an audio signal with more apparent presence, or perceived loudness. For a digital audio signal, there's only so much room to go before the maximum ceiling is reached and distortion results. Therefore, in order to turn up the quieter parts of a sound we want to hear, we also need to reduce the louder parts, rather than simply turning the whole audio signal up. Continue reading »