In a performance or entertainment sound reinforcement project, there is a question that may bother you: Should I use UHF (U-band) or VHF (V-band) wireless microphones? So what are the differences between the two, and which type is more advantageous? Today, the editor of Aiwei Audio will sort out it, let you figure out what is U-segment and V-segment!
1. The transmission signal of the transmitter
The transmitter part of the V-segment wireless microphone mainly uses several frequency multiplication circuits to obtain high-frequency signals, and the signal carrier frequency of the transmitter is fixed.
Most U-segment wireless microphone transmitters use phase-locked loop technology to obtain high-frequency signals, and most of the transmitter's frequency is adjustable.
2. Receive the transmission signal of the host
The V-segment wireless microphone receiver is also made of a fixed frequency point.
Most U-segment wireless microphone receivers are made with adjustable receiving frequency.
3. Anti-interference ability
When there is an interference signal, the V-segment wireless microphone is difficult to avoid, and the U-segment wireless microphone can easily avoid various interferences by adjusting the frequency of the transmitter and the receiver. U-segment wireless microphones used for professional performances are often made of true diversity, that is, a microphone uses two antennas to receive, and the probability of breakpoints in the use of a well-designed UHF true diversity wireless microphone is extremely small.
Of course, all microphone manufacturers in the world can't completely solve the problem of such microphone receiver being interfered by other co-frequency signals. Of course, excellent manufacturers will use technical means to minimize this possibility. The transmitter minimizes spurious emissions such as parasitics, intermodulation, harmonics, etc., while the receiver uses SQ (Squelch, squelch threshold, later Talk) or narrowband operation, frequency hopping technology and so on. In this way, the influence of interference on the system can be solved, and the wireless microphones in the system can be used more.
4. Signal transmission path
VHF radio frequency signal transmission has little reflection on small metal objects and can be diffracted; it can penetrate non-metal objects such as the human body; the loss of the feeder is low, and the antenna can be appropriately extended; the battery can be used for a long time; it is affected by VHF TV channels and paging , Letter machine and industrial pollution such as electric welding, electric motors, etc. have large interference; the usable frequency range is 61MHZ, the expandable range is too narrow, the frequency is crowded when the multi-microphone is used, and the compatible frequency is less; the dynamic range of the signal is small.
UHF radio frequency signal transmission reflects much to small metal objects, and multi-path propagation can cause interference; it shields and attenuates non-metal objects such as the human body; the loss of the feeder is large, and the receiver should be as close to the microphone as possible; larger transmission power is required, and battery The use time is short; the high frequency interference is less; the usable frequency range is 270MHZ, the expandable range is large, and the multi-microphone can be used to form a larger system; the dynamic range of the signal is large.
After comparing so many, it can be seen that the two wireless microphones have their own characteristics. But why do most people say that U-segment is better than V-segment?
For example, large-scale professional performances use UHF true diversity wireless microphones without exception. Many famous singers use UHF wireless microphones for performances. It seems that UHF wireless microphones are more popular than VHF wireless microphones?
Now mainstream wireless microphones all use U-segment work, around 500-850. Some major brands have produced microphones with G-segment (1000-2400MHZ), and most domestic manufacturers produce microphones with around 700-850MHZ. The V-segment machine is a product of the previous generation, and it is rarely used as a show now.
1. The amount of information
As we all know, the amount of information is determined by the frequency of electromagnetic waves. The lower the frequency, the longer the transmission distance, and the smaller the loaded data. The higher the frequency, the shorter the transmission distance and the larger the amount of loaded data. V wave and U wave are two directions, which is why V wave is more suitable for radio, walkie-talkie, aerospace communication, and U wave is more suitable for TV.
2. Degree of interference
Because the V band has a narrow low frequency range (180MHZ--280MHZ), there will be interference between more than 6 bands, and the U band has a wider range (500MHZ--900MH), so there will be interference above more than 60. In addition to the small loading data, this is also one of the important reasons why the V-band sound effect is not good.
Because the U-segment is a high-frequency transmission and reception, it has higher requirements for electronic vitality parts than the V-segment, and the technical content is correspondingly higher. In terms of application, the U segment is not the same segment as most frequency waves in daily life, so the chance of interference is greatly reduced. The U-segment has a wide range, and more frequency points can be misdivided to realize the use of multiple frequency points on the same occasion without interference.
There is also a real problem. For the above reasons, the microphone manufacturer will be more costly in purchasing materials for U-segment products than for V-segment products. In actual use, since most of U-segment has frequency modulation function, it is more convenient than V-segment.
This is not to say that the U segment is necessarily better than the V segment. Generally speaking, these two frequency bands of wireless microphones have their own advantages and disadvantages. This is determined by the user of the frequency band, the physical characteristics of the frequency band, and the adjustment limits of the frequency band. Therefore, it is recommended to choose the V-band for long-distance users, and the U-band for those with higher sound quality requirements.
Generally speaking, V-segment microphones are suitable for hotels, convention and exhibition centers, and teaching systems; and U-segment microphones are suitable for broadcast and television and theater performances.