Professional performance microphones are divided into three frequency bands, FM, VHF, and UHF. The following briefly introduces the performance and use occasions of each frequency band. 1. FM part: Everyone knows FM radio. The frequency of the FM radio is 88-108 MHz. The frequency of professional performance microphones in the FM band is higher than 108MHz. Generally between 110-120MHz and 120MHz, so the FM radio signal will not interfere with the professional performance microphone of the FM segment, and will be interfered by other clutter; the advantages of the FM professional performance microphone are: the circuit structure is simple, the cost is low, and it is beneficial Produced by the manufacturer; the disadvantages are: poor sound quality, frequency changes with time/environment temperature, poor reception, signal interruption, and large interference. Shouting into the microphone will cause the sound to break; use occasions: the use requirements are very low, and the sound quality requirements are not much. If you only need sound, you can choose FM wireless microphone.
2. VHF part. The very high frequency band is commonly known as the V band, and the frequency is between 180-280MHz. Due to the high frequency and low interference, frequency conversion will not occur due to crystal frequency lock, and the receiving performance is relatively stable. V-band professional performance microphones generally have two circuits: the first circuit; the high-frequency part only uses a 2003 integrated IC. These include. Signal reception, radio frequency amplification, frequency mixing and frequency discrimination are completed in one step. The sensitivity is not high, and the audio part uses 31101 lines. By compressing and expanding audio, the sound quality is much better than FM. The reception performance is improved by one level. Advantages: stable reception. Short-distance interruptions are rarely seen. Disadvantages are: the high frequency part is unstable, the sound frequency is not wide enough, the effect is not ideal in professional occasions, the use occasion: general household, the performance is relatively stable, and the sound quality is acceptable. You can choose this kind of wireless microphone.
The second circuit: the high-frequency part adopts discrete processing, high-frequency amplification, and intermediate-frequency amplification. Mixing and frequency discrimination. Step-by-step processing has better effect, higher sensitivity and more stable performance. The audio processing part adopts 571 lines, with good sound quality and wide frequency response. Advantages: stable performance, good sound quality; use occasions: KTV hall, home, small and medium-sized concerts, the effect is ideal.
UHF cross-section is commonly known as u-shaped cross-section. The frequency is generally 700-900MHz. At such a high frequency, basically no other external frequencies can interfere, and most of the U-shaped cross-sections are made of SMD components. The performance is very stable, generally u use three channels, the audio processing circuit uses the latest 571 line, the sound quality is better;