Do you know the pros and cons of each frequency band of wireless microphones?
Wireless microphone is composed of several pocket transmitter and a centralized receiver. Each pocket transmitter has a different working frequency, and the centralized receiver can receive the voice signals of different working frequency issued by each pocket transmitter at the same time. It is suitable for the stage platform and other occasions.
According to the different frequencies of use, wireless microphones are generally divided into 3 types, namely FM segment, VHF segment and UHF segment. Below we will analyze the advantages and disadvantages of the 3 types of wireless microphones and suitable places for use.
Frequency Band: F M
Everyone knows FM radio, the frequency of FM radio is 88-108MHz. Wireless microphone frequencies in the FM band are all higher than 108MHz. Generally, it is between 110-120MHz, so the signal of the FM radio station will not interfere with the wireless microphone in the FM segment, but it will be interfered by other clutter.
Advantages: The circuit structure is simple, the cost is low, and it is conducive to the production of manufacturers.
Disadvantages: poor sound quality, frequency changes with time/ambient temperature, poor reception, disconnection, and large interference. Screaming loudly into the microphone will cause staccato.
Application:The requirements for use are very low, and there is not much demand for sound quality. FM wireless microphones can be used when only sound is required.
Frequency Band: V H F
The VHF segment is used to be referred to as the V segment, and the frequency is between 180-280MHz. Due to the high frequency, there is generally little interference. Using crystal frequency locking, there will be no frequency conversion, and the receiving performance is relatively stable. V-band wireless microphones generally have two circuits.
The first circuit: the high-frequency part only uses a 2003 integrated IC. Including: signal reception, RF amplification, frequency mixing, frequency discrimination, etc. in one step. The sensitivity is not high, and the audio part adopts 31101 line. The audio is compressed and expanded, the sound quality is greatly improved compared with FM, and the receiving performance is improved by a grade.
Advantages: stable reception. Interruptions are generally rare in short distances.
Disadvantages: The high frequency part is not stable, the audio frequency response is not wide enough, and the effect of professional use is not ideal.
Application:general household or in such occasions where the performance is relatively stable and the sound quality is acceptable. You can choose this type of wireless microphone.
The second circuit: the high frequency part adopts discrete processing, high frequency amplification, and intermediate frequency amplification. Frequency mixing, frequency discrimination. Step-by-step processing, the effect is better, the sensitivity is higher, and the performance is more stable. The audio processing part adopts 571 line, the sound quality is better, and the audio frequency response is wider.
Advantages: stable performance, good sound quality.
Application: KTV hall, home, small and medium concerts...
Frequency Band: UHF
The UHF segment is generally called the U segment, and the frequency range of the UHF band is 300MHz-3000MHz.
The frequencies of U-segment wireless microphones are generally around 500 and 800 MHz. Such a high frequency is basically not disturbed by other external frequencies, and most of the U-segment components use SMD components. The performance is very stable, and there are generally three circuits in the U segment. The audio principle circuit adopts the latest 571 circuit, and the sound quality is better.
The first type: Single frequency type.
Similar to the V-band frequency circuit, high frequency amplification, and intermediate frequency amplification. Frequency mixing, frequency discrimination. Step-by-step processing, high-level amplifier is divided into several episodes for amplification, audio processing adopts 571 line design, and the sound quality is clear.
Application:when it is not satisfied with the V segment, or when the usage requirements are not very high. Or if there is interference in the environment where the V-segment machine is used, this type of model can be selected.
The second: Adjustable frequency.
This type of machine is controlled by a microcomputer program. The high frequency oscillation is controlled by a phase locked loop (PLL). Generally, there are multiple adjustable channels, and there are thousands of adjustable frequency points for selection. Effectively avoid interference, multiple machines can be used at the same place at the same time without interfering with each other. If there is interference, adjust the frequency point to other frequency points to avoid interference and squelch the noise. The audio processing adopts a new design with stable performance.
Application: This type of machine is used in many high-end KTV rooms. Small to medium concerts. Or when multiple people are required to sing at the same time, the effect is ideal.
The third type: Diversity.
The so-called diversity is diversity reception, one is single-frequency diversity, the other is adjustable frequency test diversity, this kind of machine has the functions of U-segment machine, and each channel adopts two-way receiving circuit system. If there is a dead spot in one receiving system, there is another one that can receive the signal. Effectively avoid the dead zone of the signal, greatly improve the technical level of the whole machine, ensure the stability of the received signal, and receive continuous information. This kind of machine is a relatively advanced wireless microphone. The farthest use distance can reach more than 200 meters.
When there is an interference signal, it is difficult for the V-segment wireless microphone to avoid it, while the U-segment wireless microphone can easily avoid all kinds of interference by adjusting the frequency of the transmitter and receiver. U-segment wireless microphones used for professional performances are often made into true diversity, that is, one microphone is received by two antennas, and the probability of breakpoints in the use of U-segment wireless microphones is extremely small (the well-designed UHF true diversity wireless microphones) ).
Application: all kinds of large and medium-sized concerts. This type of machine is the best choice for situations where the use environment is very demanding or the use environment is more complex.
