The scientific name of mic is actually microphone, which is an energy conversion device that converts sound signals into electrical signals. The principle of microphone is that the vibration of sound is transmitted to the diaphragm of microphone, which pushes the magnet inside to form a changing current, and the changing current is sent to the sound processing circuit behind for amplification.
In the car, the microphone is mainly used to answer the phone and play navigation voice through Bluetooth. Wireless microphones can generally be divided into three frequency bands, namely FM band, VHF band and UHF band, as follows:
1, FM band: Because the frequency of FM radio is 88- 108MHz, and the frequency of wireless microphone in FM band is higher than 108MHz, generally between110/20mhz, the signal of FM radio will not be. The wireless microphone in this frequency band has simple mechanism and low cost; But the sound quality is very poor.
2.VHF band: VHF band is generally called V band, and its frequency is between 180-280MHz. Because of its high frequency, there is less interference. At the same time, crystal frequency locking is adopted, and the receiving performance is relatively stable.
3.UHF band: UHF band is generally called U band, and the frequency is between 700-900 MHz. At such a high frequency, there is almost no interference from other external frequencies. At the same time, patch components are mostly used in U-band, which has very stable performance and good sound quality.