Audio source: such as microphone, DVD, computer, tape recorder and other equipment;

Mixer: it is the center of the system, and it is the equipment that undertakes sound source, periphery and power amplifier;

Power amplifier: it is a device that amplifies signals to drive speakers;

Speaker: it is the equipment that finally restores the original sound signal;

Peripheral equipment: various effectors, processors, suppressors, equalizers and so on connected to the mixer.