The principle and use of karaoke microphones explain the working principle of KTV microphones in detail
In recent years, karaoke has swept all corners of the country, and many audio-visual equipments have karaoke functions. Among them, the microphone is an important part. It is very important to understand the principle of the microphone and use the microphone reasonably to play the karaoke function well and get a good sound effect.
Working principle
At present, karaoke microphones widely used in commercial karaoke dance halls and home karaoke systems can be divided into wired karaoke Microphone and wireless karaoke microphone.
Wired Karaoke Microphone As the name suggests, the output signal of the wired Karaoke microphone is sent to the amplification device through a cable.
The commonly used wired karaoke microphones are mainly moving coils. The working principle is: when the sound wave acts on the diaphragm of the microphone to make it vibrate, the voice coil attached to the diaphragm is The air gap of the magnetic circuit also vibrates accordingly, cutting the magnetic field lines and generating an induced electromotive force in the voice coil. However, the electromotive force output by the microphone is very low, and a step-up transformer is usually connected to the output end of the microphone to match with the audio equipment.
Karaoke microphones are used at close range. In order to achieve good results, the microphones are required to have special proximity effect and directivity effect to improve performance and resist environmental interference. That is, the sensitivity of the microphone changes with the distance of the sound source at the low frequency end: the closer the distance, the higher the low frequency sensitivity. High-value karaoke microphones also feature bang filters to minimize excessive breath noise and pops for full, full-bodied sound reproduction. Another important feature of the karaoke microphone is that there is a control switch on the microphone shell, so that you can achieve some special sound effects when you sing. The specially designed anti-vibration measures can effectively prevent friction noise when hand-held, so that your singing bass is distinct, the treble is bright and pleasant, and the sound quality is soft and beautiful, full of appeal.
The domestic famous brand karaoke microphones mainly include the Prime series karaoke microphones. This series of microphones is the preferred product for karaoke dance halls and home karaoke systems. The representative product of household karaoke microphone is CDK404 with metal shell, which is available in black and silver-gray. Its main technical performance is as follows: the frequency response is 100Hz ~ 10kHz, the output impedance is 600Ω±30%, the free field sensitivity is -54dB (1kHz), and the weight is 300g.
Wireless karaoke microphones limit the free movement space of singers due to the cable of wired karaoke microphones, thus affecting the singer’s passionate performance and range of movement. The wireless karaoke microphone came into being. The following figure is a block diagram of the electrical principle of the wireless karaoke microphone.
The sound head of the wireless karaoke microphone converts the acoustic signal into an electrical signal, the electrical signal modulates the frequency of a carrier wave, and the frequency-modulated carrier radio signal is transmitted by the antenna. After the radio signal is received by the FM receiver, the sound signal is restored and sent to the karaoke machine. The transmitting frequency of the wireless karaoke microphones used in the home is mostly in the range of 88 ~ 108MHz, and the purpose is to use the recorder with the FM band as the receiving equipment of the wireless karaoke microphone to save money. The power of the transmitter is not large, about 100mW, so as not to interfere with other electrical equipment. The professional wireless karaoke microphone works in the high-end frequency band (150-216MHz) or ultra-high frequency band (400-470MHz, 900-950MHz) of the ultra-high frequency band, and is equipped with a dedicated FM receiver. Wireless karaoke microphones all use FM, because FM has the advantages of strong anti-interference, wide frequency characteristics, high fidelity, low noise, and high transmitter efficiency.
Key points for using karaoke microphones
When using karaoke microphones, pay attention to the following points: (1) The output impedance of karaoke microphones should be the same as yours. (2) When using more than two karaoke microphones, the phases of the two microphones should be unified; (3) Before use, the volume of the karaoke machine should be adjusted properly to avoid excessive noise. The volume burns out the amplifier and speakers. (4) When using, do not cover the mesh cover with your hands and block the sound hole, so as not to affect the performance of the microphone and reduce the singing effect. (5) When storing the microphone, it should be dust-proof, shock-proof, moisture-proof and magnetic-proof.
If you can use the karaoke microphone correctly, the singing effect will be greatly improved. When singing weak voices, the microphone should be close to the lips, and the timbre becomes deep, real and delicate; when singing strong voices, the microphone should be kept away from the lips, so that the timbre becomes bright, rough and not explosive.
The karaoke microphone is the entrance of the entire karaoke system. If it is improperly selected, used and installed, its noise and distortion will be input into the karaoke system, which will affect the sound effect of karaoke singing. People often say, “Illness comes from the mouth”, please pay attention to this when performing karaoke singing.
