What is Crest Factor?
Crest factor is the ratio between the peak level of a signal and its average (RMS) level, usually given in decibels. A high crest factor means sharp peaks above a lower average; a low crest factor means the signal is dense and heavily controlled.
A pure sine wave has a crest factor of about 3 dB. Drums, plucked instruments and dynamic mixes have much higher values because their transients rise far above the average level. Compression and limiting lower the crest factor by pulling the peaks closer to the average.
Crest factor is a quick way to tell how much punch is left in a mix or master. If it gets very low, transients like kick and snare hits start to lose their impact, even though the track sounds louder.
It is closely related to the peak to loudness ratio (PLR), which uses the LUFS loudness instead of the RMS level as the average.
Put it to work
Measure the peaks, average level and dynamics of your track.
Analyze Loudness and Dynamics