RMS Level

RMS (expanded view)

Root Mean Square (RMS) is an audio measurement that correlates signal energy with a reference signal. Neither a peak, nor an average, RMS is derived by squaring all the instantaneous voltages from a waveform, averaging the squared value, and then taking the square root of that value. Thus, RMS is a mathematical measurement devised to characterize the level of a given signal. RMS Level is a measurement that is very helpful in describing the energy of a waveform in RMS values. RMS levels are similar to average values and do not vary much even when high transient peaks are presented. The ratio between the Peak and the RMS is called the crest factor. The meter is calibrated to display 0 dB with a sine wave input at 0 dBFS (Full Scale). These meters are measured in dB and range from –96 to 0 dB. A square wave has a crest factor of 1.0. The RMS meter is calibrated for the crest factor of a sine wave such that a digital peak-to-peak signal (0 dBFS) will report 0 dB.

RMS

Peak to Peak

RMS = Peak / = Peak x 0.0707

Peak = RMS x 2 = RMS x 1.414

Meter Graph : What the Meters Measure

User’s Guide