The earliest microphones all had cables. It’s no problem to use karaoke in a recording studio or a small space. It’s okay to sing a song quietly on the stage, but it’s not easy to show some dancing. Up. Therefore, when performing on stage now, people are more inclined to use wireless microphones.
The convenience of wireless microphones is obvious to all. In addition to stage performances, they are also widely used in KTV, conference rooms and other occasions. When most users use wireless microphones, they think that they can talk as long as they connect to the device. In fact, there are many techniques and precautions when using wireless microphones. If you don’t understand its working principle and characteristics, you can’t really use wireless microphones. .
How does a wireless microphone work?
Wireless microphone, also called wireless microphone, consists of two parts: transmitting and receiving. Among them, the transmitting part is powered by a battery, and the microphone converts the sound into an audio signal. After processing by an internal circuit, the radio wave of the audio information can be transmitted to the surrounding space.
The receiving part is generally powered by a power supply. First, the receiving antenna receives the radio wave emitted by the transmitting part, and then processes the internal circuit to extract the audio signal, and then transmits it to the PA system through the output signal line to complete the wireless audio signal. transmission.
After understanding the working principle of wireless microphones, let me talk about what issues need to be paid attention to when using wireless microphones.
1. Pay attention to impedance matching
The output impedance of the wireless microphone is the same as the input impedance of the amplifier, which is the best match. If the mismatch ratio exceeds 3:1, it will have an impact on the audio transmission effect. Although it can be used, there will be significant loss of high and low frequencies.
2. Pay attention to working distance and proximity effect
When talking or singing with a handheld wireless microphone, the working distance between the microphone and the mouth is generally 750px-1000px. Too far away will increase reverberation, and too close distance will cause audio distortion due to strong signals and affect clarity. It is the "proximity effect", the low-frequency sound will be significantly improved when broadcasting at close range.
Of course, the effect of proximity effect on the sound is not completely undesirable. Professional singers with rich experience and profound knowledge sometimes use this effect to change the sound effect.
3. Pay attention to the angle between the sound source and the microphone
Wireless microphones have a certain effective angle. Under normal circumstances, the sound source should be aligned with the center line of the microphone as much as possible, because the greater the deviation angle, the greater the effect loss.
Fourth, pay attention to the placement and height of the wireless microphone
Sometimes when we turn on the microphone, we will hear a sharp and piercing sound. This is caused by placing the microphone and the speaker too close. If it is farther away, it will be fine.
When using a microphone stand, the height of the wireless microphone should be the same as the height of the performer’s mouth, so as not to be too high or too low to affect the sound reception.
Five, pay attention to remove the battery in time
Wireless microphones generally need to be installed with batteries. If the battery voltage drops, the sensitivity of the microphone will decrease and the distortion will increase. Therefore, when you do not use it for a long time, you must remember to remove the battery in time. The battery should be replaced in time if it is not completely exhausted.