1. When the current I passes through the voice coil in the magnetic gap with the magnetic field intensity B of the speaker, the voice coil will receive an electrical force F=BLI(L is the length of the voice coil), and the force direction shall be according to the left-hand rule. Here voice coil is not only one of the factors of the force, but also the recipient of the force, but also plays a considerable role in the size of the force.

2. When the vibration system including the voice coil vibrates at the speed V after the force is exerted, the induced voltage BLv will be generated in the voice coil, and its direction is in accordance with the right hand rule and opposite to the original current direction. The voice coil is both the initiator and the receiver of damping.

3. If the mass of the voice coil is relatively large, the resonant frequency of the vibration system will be reduced, but at the same time, the efficiency and sensitivity of the speaker will be reduced, and the upper limit of the loudspeaker playback high frequency will be reduced; If the quality of the voice coil is relatively small, the resonant frequency of the vibration system will be increased, and the efficiency and sensitivity of the speaker will be improved, and the upper limit of the loudspeaker playback high frequency will be increased.

4. Dc resistance and inductance of the voice coil determine the impedance and impedance curve of the speaker, and also affect Small parameters such as Q0 value of the speaker. The impedance will affect the connection efficiency and damping coefficient of the amplifier. When the amplifier is output at constant voltage, the lower the impedance, the higher the current, the higher the sound power of the loudspeaker output, and at the same time, the greater the risk of damage to the loudspeaker.

Voice coil, in turn, has a lot to do with speaker distortion. When the voice coil is placed in a magnetic field, the distribution of the magnetic field is uneven, and the distribution of the magnetic field is only uniform over a certain range. When the voice coil is in operation, the magnetic flux density B is not uniform, resulting in uneven force, resulting in distortion.