Dynamic range is the dB difference between the loudest and quietest signals in a program

Dynamic range is the ratio, expressed in decibels, between the maximum and minimum signal levels in a system or program. In a sound system the effective dynamic range is limited at the bottom by the noise floor and at the top by the clip point. Headroom is the gap between the nominal operating level and the clip point; it accommodates peaks without distortion. Signal-to-noise ratio (S/N) is the gap between the nominal level and the noise floor. The full usable dynamic range equals S/N + headroom. A typical professional sound system has a dynamic range target of 90+ dB to accommodate music from whisper to peak transient.

Examples

A console with a noise floor at –90 dBu and a clip point at +24 dBu has a full dynamic range of 114 dB. If the nominal level is 0 dBu, S/N is 90 dB and headroom is 24 dB.

Assessment

Given a system with –80 dBu noise floor, 0 dBu nominal level, and +20 dBu clip point, calculate: (a) S/N ratio, (b) headroom, (c) full dynamic range.