Peak Programme Meter. A meter designed to register the approximate peak amplitude of a signal, rather than the average level indicated by, for example, a VU meter. However, PPMs have a defined integration time (typically 10ms) which means that they actually under-read on the fastest transient peaks. (cf. VU Meter)

A signal derived from the channel path of a mixer after the channel fader. A post-fade aux send level follows any channel fader changes. Normally used for feeding effects devices.

A powered speaker is a conventional passive loudspeaker but with a single power amplifier built in or integrated with the cabinet in some way. The amplifier drives a passive crossover, the outputs of which connect to the appropriate drive units.

A unit designed to convert mains electricity to the DC voltages necessary to power an electronic circuit or device.

A device which accepts a standard line-level input signal and amplifies it to a condition in which it can drive a loudspeaker drive unit. The strength of amplification is denoted in terms of Watts of power.

A form of electrical potential divider in which the ratio of the upper and lower resistances can be changed either with a rotary control or slider (eg. a fader).

Work done to a recording.

A gliding effect that allows a sound to change pitch at a gradual rate, rather than abruptly, when a new key is pressed or MIDI note sent.

A connection for the input or output of data or other signals. In the context of loudspeakers it refers to the vent in a bass reflex cabinet.

A device placed between a sound source and a microphone to trap wind blasts - such as those created by a vocalist’s plosives (Bs, Ps and so on) - which would otherwise cause loud popping noises as the microphone diaphragm is over- driven. Most are constructed from multiple layers of a fine wire or nylon mesh, although more modern designs tend to use open-cell foam.