Although there are different sound systems according to different requirements and tasks, as well as different occasions, and there are significant differences in the number of functions and scale of the same type of sound system, there are also common rules in the composition and design of sound systems. The composition of professional audio systems is generally centered around the mixing station and captures the origin and development of sound signals. The so-called "origin" refers to the connection from the program source equipment to the mixing station, and the "de pulse" refers to the connection from the main output of the mixing station to the subsequent equipment. Depending on the system, it can be connected to recording equipment or amplifying equipment. In addition, audio processing equipment can be connected around the mixing station according to different needs. For home audio systems, the front amplifier (preamplifier) is the center of coordination.