The working principle of the speaker is based on the principle of the motor. The speaker converts electrical signals into sound signals. The core of the speaker is that the conductor with electricity moves under the action of force in the magnetic field. Specifically, when the audio current passes through the voice coil of the speaker, an alternating magnetic field is generated. This alternating magnetic field interacts with the constant magnetic field of the permanent magnet, causing the voice coil and the diaphragm to vibrate, thereby making sound.