With the increasing use of video conference, people’s demand for video conference is higher and higher. For video conference, people will say that video is more important. In fact, in video conference, audio is the most important thing. They think that the communication between participants is mainly realized through audio dialogue or discussion. As long as there are pictures in video conference, it is best if they can clearly perform But the most persuasive thing is audio. Having good video and ordinary audio is much more useful than having good audio and ordinary video.

Of course, due to the low attention paid to audio products, there is a high probability of audio problems in the process of video conference. Here, Xiaolei summarizes the audio problems of video conference encountered in practice, so as to find the causes of problems quickly when there are problems.

Soft voice during audio call

One

This mainly shows that the voice from the other side is very light, and it needs to be very powerful to hear what the other side is talking about. Generally speaking, the problem lies in the acquisition of sound. We can first test our own speakers or speakers, and then use the local computer to play the test to see whether the volume is large enough. If we are sure that our audio downlink is normal, we can basically judge that the problem lies in the uplink. Generally, we can adjust the input (recording) volume of the device. This requires special signature, which is to adjust the recording volume Volume, in fact, many people only adjust the sound of the speaker, but don’t know the volume adjustment of the recording. They always respond that the sound is light, but when they ask the other party to adjust the volume of the recording, nine times out of ten they are wrong.

There is a lot of noise during the audio call

Two

There are two main effects on the noise level. One is that there may be noise sources such as fans and air conditioners during the conference. However, ordinary conference audio pickup products do not have special noise processing, which leads to the noise being picked up. The second is that the audio goes up. The volume of the recording is too loud, which leads to a large sound collection for slight actions, causing noise, Of course, sometimes there are some functions in the conference software, such as noise reduction, squelch and so on. If they conflict with the software, it is easy to cause noise.

You can hear your own voice during the video conference

Three

In the process of video conference, it is found that you can hear your voice coming back. For example, when many mobile phones use hands-free, this kind of situation is easy to occur. This kind of situation is mainly because the audio equipment is not well chosen. Although the current video conference software has the function of eliminating echo, none of them can really eliminate echo, so you need the audio equipment at the back and front end To match. If limited by the conditions, it can reduce the sensitivity of audio input equipment, increase the space distance of pickup equipment, loudspeaker and power amplifier, reduce the sound and improve the echo through the distance effect.

During the video conference, it is found that there are magnetic sounds, sometimes harsh sounds

Four

This problem is called howling. From the perspective of practical application, there are two situations that can cause this situation. One is that the local speaker releases the recorded sound, which causes the local howling. This problem can be solved by disconnecting the video conference, and then directly speaking to the pickup product to see whether the sound will come out of the local speaker. If it does, it needs to be set, generally in the playback options Remove the audio output of the pickup device and make sure that no local amplification will cause squealing. The second reason is that the echo on both sides leads to squealing. This problem is mainly the echo product, which needs to be eliminated to achieve no squealing.

The voice is not continuous during the audio call.

Five

If the above problems occur, first check the network cause, whether there is delay in the network, check the video options of intercom to ensure that there is no network cause. After the network problem is eliminated, if the problem still exists, you need to disconnect the software, because sometimes the software also has conflicts, such as QQ in the multi-party call process, the main initiator and either party will have good results, but It is easy for other parties who are not the main sponsor to have intermittent and incoherent voice, which is related to the function of the software.

No sound output in video conference

Six

When encountering such problems, first check whether the local area is normal. Generally speaking, the speaker, software, computer recording and other steps are used to analyze the local problems. If there is no problem in the local area, it is generally that the remote area is not transmitted. In this way, it is necessary to let the remote area eliminate the problem first, and whether the sound is up (recorded). If there is no problem, check the video software to see if the audio input device has been set as the pickup device you need. If not, please select. Of course, some conference software needs to be the main person to speak, it needs to turn on the corresponding functions, and then test.

The voice changes very seriously. I can’t hear it clearly

Seven

Generally speaking, the above problems are software conflicts, or you need to add hardware products after you open video software. Because it is easy for the computer end to have software conflicts when dealing with such problems, resulting in failure to work normally, you need to eliminate the software end problems first, make sure they are OK, and then come to see if there is any problem.

The sound delay is quite severe

Eight

When the sound delay is severe, first test whether the network is in good condition. If you are in the LAN, search the LAN once to see if someone is using the network to watch video or other software with large traffic, such as

1. Maintenance of projector

In the use of projector, the most important problem is to keep good heat dissipation. The projector has two power switches, one is the soft switch (power key) and the other is the hard switch (power switch). After the use of the projector, first press the power key to turn off the projector. In fact, the projector is not really finished at this time, and the cooling fan on one side is still rotating. Because the heat released by the projector is huge, the manufacturer has designed a three to five minute cooling process. If the projector is turned off at this time, the internal heat cannot be discharged, and the LCD or bulb will be burned. Turn off the hard switch after the fan stops rotating. In general, the projector should be closed for four or five hours after a continuous use, so that it can rest. This will extend the service life of light bulbs and LCD panels. Do not vibrate the projector during projection.

2. The screen color of projector is different from that of display

When the color of the projector screen is different from the color of the display, it is possible that the VGA cable is not connected properly or a cable of a certain color is dropped inside, in addition, the LCD board may be burnt out.

3. Some characters of the projector are not completely displayed on the screen

When some characters of the projector are not completely displayed on the screen, it is possible that the resolution of some projectors is not enough, the display of characters and graphics is not complete, and the resolution of the computer can be reduced to see whether it will be completely displayed. If not, one of the three LCD chips has been burnt out.

4. The projector appears dark yellow or the color is not full

If the projector appears dark yellow and the color is not bright. It may be that the life of the bulb is over, and the bulb shall be replaced (it is worth noting that the service time of the bulb shall be reset after replacement, otherwise the new bulb will be easily aged according to the old time.

5. Can I use two microphones of the same frequency at the same time

Cannot be used at the same time. Wireless transmission cannot be “mixed” in the air. Even at the same frequency, the receiver cannot mix two transmission signals. For example, it is impossible for two FM radio stations to send signals on the same frequency. Because this will cause confusion, resulting in audio distortion. All in all, each wireless transmitter should have a separate receiver with its own frequency.

6. What is the frequency difference between wireless microphones to avoid interference?

It depends, but at least 4MHz. We can’t answer this question explicitly here, because it involves complicated calculation. In general, the frequency gap required by cheaper wireless systems is large, because their receivers are simple in design and few in selection. This limits the number of channels it is compatible with. The system with higher price has better filtering performance, closer distance between channels, and more compatible channels. If we say “you don’t want to make your own calculations”, we must be right. If you need, please contact the manufacturer or agent, they will help you calculate. Most manufacturers have calculated the compatible frequencies for each of Shure’s wireless features, so you don’t have to do these tedious mathematical calculations yourself.

7. UHF is better than VHF, right?

These two frequency bands for wireless microphones have their own advantages and disadvantages. This is determined by the users of the frequency band, the physical characteristics of the frequency band, and the adjustment limit of the frequency band.

The following are the advantages of UHF over VHF:

? UHF band is not “crowded” with VHF band.

? UHF with flexible frequency is widely used.

? UHF features provide more compatible systems. [for example, Shure LX and SC (VHF band) systems can only provide 12 compatible channels, while Shure UHF band systems can provide more than 100 compatible channels. ]

? UHF system has higher power output than VHF, wider frequency shift, better dynamic range and better signal-to-noise ratio.

VHF is superior to UHF in several aspects:

1. VHF system is cheaper.

2. VHF has a larger transmitting range under a specified transmitting power.

3. VHF signal transmission, even through non-metallic materials. VHF has a long wavelength and is not easily absorbed by human body.

8. Can UHF system be compatible with VHF system?

Yes, UHF can be compatible even if the maximum number of compatible VHF systems is used. (however, the current VHF antenna, VHF separator or VHF antenna distribution amplifier of UHF receiver cannot be connected.).