In a performance or entertainment sound reinforcement project, when choosing a wireless microphone, whether to use a UHF (U-segment) or VHF (V-segment) wireless microphone may bother you. 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. A system with multiple channels working at the same time uses true diversity reception. However, experienced design and construction personnel usually try both systems before the performance, mainly to check whether the electromagnetic space on site is suitable for using your wireless microphone.
The V segment does interfere with each other when multiple sets of wireless microphones are used. Of course, it cannot be said that there is no U segment, but it has a large expansion range and can be adjusted as much as possible. So what are the differences between the two? Which type is more advantageous? The editor will sort out it, let you figure out what is U and V segment!
The difference between U-segment and V-segment wireless microphones
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 in professional performances are often made of true diversity, that is, a microphone uses two antennas to receive, the probability of breakpoints in the use of U-segment wireless microphones is extremely small (the UHF true diversity wireless microphone with excellent design ).
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 of the multi-microphone is crowded, and the compatible frequency is small; 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?
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.
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 when there are 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.
Now with the development of technology, sound processing becomes more and more professional, requiring long-distance selection of V-band, and U-band for sound quality requirements. The two frequency bands used for 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.
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.
1. Do not hold the mesh head of the microphone with your hand
The receiving part of all microphones has a certain degree of directivity. If you hold the grille part with your hand, the directivity and frequency response of the microphone will be changed. Due to the gathering effect of the palm, feedback, whistling and other effects will be generated.
2. Do not hold the antenna transmitting part of the microphone
In general handheld microphones, the transmitter circuit and antenna are located at the lower part of the microphone (the end far from the microphone head). When a human hand touches the antenna, most of the radio frequency energy is lost because it cannot enter the air, which reduces the use range of the wireless system and affects Receive the effect.
3. Properly maintain the distance between the microphone and the mouth
When using a handheld wireless microphone, it is generally better to keep the distance between the microphone and the mouth at 5-10cm. Too close will produce a close-talking effect, and too far to sound very light, which will destroy the sound quality; when using a lavalier microphone, it is necessary to prevent The microphone is too far away from the mouth, try to be as close to the mouth as possible; when using a headband microphone, it is necessary to avoid the mouth directly facing the microphone head and avoid the impact of the vocal airflow. You should move it to both sides.
4. Avoid pointing the microphone directly at the speaker
If you point the microphone directly at the speaker, the system forms a closed loop, which will produce positive feedback (howling), which must be avoided.
5. Avoid placing two wireless microphone transmitters close together
6. Do not tap the microphone sound-absorbing head to avoid damage to the microphone head