Matrix mixer

A matrix mixer is an audio electronics device that routes multiple input audio signals to multiple outputs. It usually employs level controls such as potentiometers to determine how much of each input is going to each output, and it can incorporate simple on/off assignment buttons. The number of individual controls is at least the number of inputs multiplied by the number of outputs.

Matrix mixers may be incorporated into larger devices such as mixing consoles or they may be a standalone product. They always have routing and level controls and may also include other features. Matrix mixers are often used in a complex listening space to send audio signals to different loudspeaker zones. They may be used to provide the producer or director different blends of a mixing project for television, film or recording studio.

In professional audio, a matrix mixer is used to route audio signals from multiple sources to different destinations. It may be a standalone device or embedded within another, larger product such as a mixing console, digital audio workstation or digital signal processor.

An analog matrix mixer contains a number of simple electronic mixer circuits, the quantity being the number of inputs multiplied by the number of outputs. Each electronic mixer controls the level (gain) of one input going to one output. The level control is usually a rotating potentiometer (called a "pot"). Each row of electronic mixer circuits, one from each input, feeds a summing amplifier or combining amp at the output. A fader (a linear potentiometer) may be used to control the level of each output signal. Other controls may include a mute button for each input/output intersection, a mute button for each input, a mute button for each output, and buttons that invert the input signal polarity. The output signals of the matrix mixer may be digital, or they may be balanced or unbalanced analog. It is possible in a matrix mixer to combine an all-analog signal path with digital control of level.

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