The magnets on the speakers mainly include ferrite magnets and NdFeB magnets. According to the application, ferrites can be divided into five categories: soft magnetism, hard magnetism, gyromagnetism, moment magnetism and piezoelectric magnetism. NdFeB magnets are widely used in electronic products, such as hard drives, mobile phones, headphones, and battery-powered tools.

When the current that changes in the sounding principle of the speaker is passed through the speaker, the magnet becomes an electromagnet. It is a conversion of electrical energy into sound. When different electronic energy is transmitted to the coil, the coil generates an energy that interacts with the magnetic field of the magnet. This interaction causes the paper plate to vibrate. Because the electronic energy changes at any time, the coil of the speaker It will move forward or backward, and the direction of the current changes constantly. The electromagnet also keeps moving back and forth due to the "forced movement of the energized wire in the magnetic field", so the paper plate of the horn will follow the movement, which makes the air flow. The density changes to produce sound.

Without magnets, the speakers can't produce sound. Magnets are used to generate magnetic fields.

When the speaker receives the electrical signal output by the audio source device, the current will pass through the coil on the speaker and produce a magnetic field response. The current passing through the coil is an alternating current, and its positive and negative electrodes are constantly changing; the positive and negative electrodes will attract each other when they meet, and the coil will move backward (in the box) by the attraction of the magnet on the speaker; the positive and negative electrodes will repel each other when they meet. , the coil moves outward (outside the box).

This closing and expanding rhythm generates sound waves and air currents, and produces sound, which is the same effect as the vibration of a speaking throat.

An alternating current flows through the voice coil of the speaker, which produces an alternating magnetic field. This magnetic field is in a fixed magnetic field, and the two magnetic fields will produce two different effects of like-sex attraction and opposite-sex repulsion, so that the voice coil has two different movements of being sucked in and being pushed out. The paper cone connected with the voice coil pushes the air to move back and forth, producing the same air vibration movement as the alternating current.

If there is no fixed magnetic field, and a non-magnetic iron core is installed in the voice coil, no matter whether the AC current is a positive half-wave or a negative half-wave, the magnetic field of the voice coil and the movement of the iron core are all pulled together. It becomes a pulse movement, and the sound produced is of course distorted.

If there is no iron core in the middle of the voice coil, the magnetic field of the voice coil has no object to act on, and it will not have any movement itself, and even the distorted sound will not come out.