The core component of the audio device is the speaker, the key component of both the audio and the headset. The speaker is composed of several key components: T iron, magnet, sound ring and diaphragm. When the AC current passes through the sound ring of the horn, the corresponding magnetic field is generated in the sound ring, which interacts with the magnetic field generated by the own magnet on the horn, which makes the sound ring vibrate with the audio current in the permanent magnet of the speaker's own magnetic field. The diaphragm and the sound coil are connected together, when the sound coil vibrates together with the horn diaphragm, pushing the surrounding air to vibrate, and the speaker thus produces a sound. Speaker is a kind of transducer that transforms the electrical signal into an acoustic signal. The performance of the speaker has a great impact on the sound quality, and the magnet in the speaker largely determines its performance. Electroacoustic field is including speakers, receiver, microphone, alarm, stage audio, car audio, etc.