The basic structure of nd-fe-boron magnet in electroacoustic device engineering is the same. Rare earth permanent magnetic materials provide a constant air gap magnetic field; The coil of the wire is suspended in the air gap and the magnetic field is perpendicular to the conductor.

The electroacoustic devices in the neodymium-iron boron magnets include speakers, hearing AIDS, pickup, stereo headsets, electroacoustic sensors and telephone receivers. All the materials used are neodymium iron boron magnets, especially the third generation rare earth ndfeb permanent magnet system, which makes the device small, light and music.

At present, the development trend of mobile phones is multi-function and miniaturization, and the high-performance Nd- fe-b permanent magnet material is also playing a key role in the miniaturization of the mobile phone and the multi-function ndfe-boron magnet.

Loudspeaker structure, work force in the direction of the voice coil and size along with the direction and strength of current change, the attacks on the voice coil in the magnetic field force, when the direction of the magnetic field B clearance and voice current f in a particular direction between shun, depending on the left hand rule, under the direction of up, under the force of the size of the force can be calculated.