Use wireless microphones to use wireless microphones.

The working principle of wireless microphones:

The wireless microphones is mainly composed of the transmitting part and the receiving part. The transmitting part is powered by batteries, and the microphones dynamically converts it into audio signals, which are then processed by an internal circuit to transmit radio waves containing audio information into the surrounding space. The receiving part is generally powered by the municipal electricity. The receiving antenna receives the radio wave announced by the transmitting part. The audio signal is extracted by the internal circuit processing and sent to the sound reinforcement system through the output signal line. Then the wireless transmission of the audio signal is completed.

After knowing its operation principle, let's take a look at the matters needing attention in the use of wireless microphones.

1. Impedance matching

When using a wireless microphones, the same output impedance of the wireless microphones and the same input impedance of the amplifier are the best matching. Assuming that the mismatch ratio is above 3:1, the transmission effect will be affected. For example, when a 50 wireless microphones is connected to an input impedance 150 amplifier, although the output can be increased by nearly 7Db, the high and low frequency dynamics are significantly discarded.

2, interval and proximity effect

Generally, the operating interval between the wireless microphones and the mouth is 750px - 1000px. Assuming that the interval is too far, the echo increases and the noise increases relatively. When the interval is too close, it will be distorted due to excessive signal and low frequency noise will affect speech intelligibility. This is due to the "close talk effect" of directional microphoness, that is, low-frequency sound will be significantly advanced when broadcasting at close intervals. However, sometimes the singer intends to use the "near effect" to make the singing more beautiful and pleasant.

3. The viewpoint between the sound source and the wireless microphones.

Every wireless microphones has its own point of view. Generally speaking, the sound source should deal with the quasi-wireless microphones center line. The bigger the deviation angle between the two, the bigger the pitch loss. Sometimes when you use a wireless microphones, it has a "boom" dynamic, and then it deflects some of the viewpoints, you can reduce some.

4. locations and height of wireless microphones

When amplifying, the wireless microphones should not be placed close to or aligned with the speaker, or it will cause a scream.

The height of the wireless microphones should depend on the height of the sound source, assuming that one speaker or several singers, the height of the wireless microphones should be with the singer's mouth; when the number of people is large, the wireless microphones should choose a uniform height, and properly allocate the singer and accompaniment as well as the position of the various instruments in the team, not to make the sound. The noise is too light, and all dynamic must be within the useful viewpoint of the wireless microphones.

Wireless microphones should be used to prevent knocking or falling. It is not advisable to test the microphones by blowing or knocking, otherwise it will easily damage the wireless microphones.

When a wireless microphones is used outdoors or when recording voice, a windshield should be used to prevent the "pop" of the incoming wind. The wind shield can also prevent dirt from smear the wireless microphones.

5. Remove the battery in time.

Wireless microphones (such as EK-88) is powered by batteries. Assuming that the voltage drops, the sensitivity decreases and the distortion increases. Therefore, when the dynamic variation, should check the battery voltage, when the wireless microphones is not used, should turn off the power switch, long-term use should be taken out of the battery.