The function of microphone: to receive the sound wave and turn it into the corresponding mechanical vibration, and then generate the corresponding electrical signal from the mechanical vibration to complete the acoustic electrical conversion.
The most commonly used microphones are: moving coil microphone and capacitor microphone. These two microphones are pressure type sound wave receivers, that is, they respond to the sound pressure at a point in space. And both of them belong to passive microphone, but their working principles are different.
Moving coil microphone
The moving coil microphone is made according to the principle of electromagnetic induction. The diaphragm receiving the sound wave vibrates and drives the coil in the constant magnetic field to generate an alternating induction electromotive force, which completes the conversion of sound energy to electric energy.
Advantages: simple structure, easy to use.
Disadvantages: low sensitivity, narrow frequency range, poor transient response compared with condenser microphone.
The capacitance microphone is based on the diaphragm which receives the sound wave to form the capacitance. After the forced vibration, its electrical capacity changes to produce an alternating voltage, thus completing the acoustic electric conversion.
Advantages: wide frequency range, high sensitivity, small distortion, good sound quality
Disadvantages: complex structure, high cost, limited storage and use conditions.
High quality dynamic microphone is often used in pop music and entertainment light music, because it can provide high sound pressure level and good fidelity. Moreover, it is highly reliable and does not need the supply of power supply voltage. Therefore, in general occasions, especially in sound reinforcement, dynamic microphone is often used. Because of its wide frequency range, high sensitivity, low distortion and good sound quality, condenser microphone is often used in recording and professional performance.