An electronic console normally used for switching between and/or combining audio from two turntables. Controls typically at least consist of: one cross
fader for switching between and combining tracks, two up
faders which control the volume levels of the seperate audio feeds, multiple equilizers on seperate channels for limiting the amount of bass, mid-range, and treble in the output, and a master
volume control for limiting the mixer output. Mixers have been in use for decades and have become an essential part of DJing.