1. Sound source equipment (DVD, CD, MP3, MP4, computer, mobile phone, microphone and other sound source output equipment);

2. Audio signal dynamic processing equipment (compressor, effector, mixer, audio processor, equalizer and other audio signal processing equipment);

3. Audio signal amplification equipment (pre-stage power amplifier, post-stage power amplifier, digital power amplifier and other analog power amplifiers, equipment);

4. Sound restoration equipment (full-range speakers, ceiling speakers, sound columns, line array speakers, array speakers, tweeters, subwoofers, etc.),

Specifically, it includes power amplifiers, peripheral equipment (including compressors, effects, equalizers, exciters, etc.), speakers (speakers, speakers), mixers, sound sources (such as microphones, musical instruments, VCDs, DVDs) display equipment, etc. Add up a set. Among them, speakers are sound output devices, speakers, subwoofers, etc. A speaker includes three types of speakers: high, low, and medium, but not necessarily three.