The components of the audio can be roughly divided into the audio source (signal source) part, the power amplifier part and the speaker part from the hardware.

Audio source: The audio source is the source part of the audio system, where final sound of the speaker comes from. Common audio sources are: CD players, LP vinyl players, digital players, radio tuners and other audio playback devices. These devices convert or demodulate audio signals in storage media or radio stations into audio analog signals through digital-to-analog conversion or demodulation output.

Power amplifier: The power amplifier can be divided into front-stage and rear-stage. The front-stage preprocesses the signal from the audio source, including but not limited to input switching, preliminary amplification, tone adjustment and other functions. Its main purpose is to make the output impedance of the audio source and the input impedance of the rear stage is matched to reduce distortion, but the front stage is not an absolutely necessary link. The rear stage is to amplify the power of the signal output by the front stage or the sound source to drive the loudspeaker system to emit sound.

Loudspeaker (speaker): The driver units of the loudspeaker is an electro-acoustic transducer, and all the signal processing parts are ultimately prepared for the promotion of the loudspeaker. The power-amplified audio signal moves the paper cone or diaphragm through electromagnetic, piezoelectric or electrostatic effects to drive the surrounding air to make a sound. The speaker is the terminal of the entire sound system.