crest factor« BACK TO DICTIONARY INDEX
(n.) The term used to represent the ratio of the peak (crest) value to the RMS value of a waveform measured over a specified time interval. A sine wave has a crest factor of 1.4 (or 3 dB), since the peak value equals 1.414 times the RMS value. Music typically has a wide crest factor range of 4–10, which may be translated to 12–20 dB. Headroom is an important factor when recording music, because the peaks occur 12–20 dB higher than the RMS value of sound levels.