An electronic device which accepts several audio sources (microphones, turntables, tape decks, etc.) and allows them to be combined into one audio output under a user's control. Typically they have slide pots or knobs to adjust what amount of each audio source is added ("mixed") into the output.

Mackie makes high-quality mixers with a wide range of number of inputs. Behringer sells cheaper clones of many of Mackie's mixers at a lower cost.