The mixer or preamplifier is the component of the sound system that is responsible for mixing the signals of CD players and other devices with line output and the signal (or signals) of the microphones. It is the device in which we will adjust the volume balancing the sound of the microphone with that of the music. Apart from the necessary volume controls they usually have tone controls (bass and treble).

  The main differences between them is the number of line and mic inputs, as well as the presence or absence of Master or general volume control (to set a maximum volume from which no more can be raised), front inputs for auxiliaries devices, etc.

  This component connects between the wireless system and the power amplifiers.