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Common faults and solutions of sound reinforcement system

发布时间:

2020-12-22 19:33

1. The sound reinforcement system sometimes makes a "click" sound, especially in the process of playing music, this phenomenon continues to appear
 
 
 
The cause of the failure: the connection line between the equipment of the sound reinforcement system has a virtual welding phenomenon. When there is a music signal, the virtual solder joint makes the sound signal intermittently
 
Solution: (1). It is necessary to thoroughly check the wiring of each channel equipment, and it is best to re-solder each connection point
 
           (2) If you thoroughly check the solder joints of each connection, there is still a "click" phenomenon, it may be that the connection wire is disconnected, check each wire with a multimeter, and replace the cable with a broken wire inside
 
 
 
2. No sound from the sound reinforcement system
 
 
 
The cause of the failure: the power plug of one or several of the serially connected audio equipment is not plugged in properly
 
Solution: Check the power connection board to make the socket contact well
 
 
 
3. When the sound reinforcement system is muted, the hum is severe
 
 
 
The cause of the failure: the connection shielding wire of each channel device is in poor contact or soldered
 
Solution: carefully check the shielded wires between the devices, and try to use welding
 
The cause of the failure: the device with the three-pin power plug is connected to the socket of the two-wire input, and the two-stage live wire and the neutral wire are reversely connected
 
Solution: The two-wire input socket must be reversed, the neutral wire and the live wire. Generally, the left foot of the socket is the live wire, and the right foot is the neutral wire. The power plug board should be equipped with three pins, and the upper middle pin should be connected to the earth wire to ensure the safety of electricity
 
Cause of failure: Some audio equipment uses two-pin plugs, but some devices must use three-pin plugs, otherwise there may be AC ​​induction phenomenon during the connection, leading to hum
 
Solution: Turn the power plug of the two-pin plug audio equipment upside down
 
 
 
4. During the sound reinforcement process, a group of speakers or two groups of speakers on the left and right channels are suddenly silent
 
 
 
Cause of failure: Under normal circumstances, it is caused by the overload of the power amplifier or the sound power of the speaker
 
Solution: (1), replace the power amplifier or speaker
 
           (2). Replace the high-power transistors with different matching pairs to repair the power amplifier. It is necessary to pay attention to the occurrence of this situation, which is caused by overload, and attention should be paid to operational problems when tuning. In order to protect the power amplifier or speakers, the sound reinforcement system can consider adding a limiter
 
 
 
5. In the karaoke hall, the vocals of the singers are separated from the music accompaniment played, and they do not merge
 
 
 
The cause of the failure: The left and right channels of the audio source enter the mixer, and the sound and image adjustment buttons on the corresponding channels are placed in disorder, resulting in confusion
 
Solution: Correct the adjustment of the corresponding channel panning knob so that the output signal of the mixer retains the panning of the original sound source
 
The reason for the failure: the room equalizer only compensates for the music sound, or the room equalizer room equalization curve adjustment is unreasonable
 
Solution: readjust the room equalization compensation curve
 
 
 
6. When the audio system and the lighting system are running at the same time, the AC noise of the audio system is very large, and after the lighting system is turned off, the audio system is running but the AC noise cannot be heard
 
 
 
Cause of failure: The sound system and the lighting system share the same single-phase power. The thyristor of the lighting system has a large working current, and it is an AC pulse type, which is directly coupled to the input end of the expansion device through the power lead, thereby generating a large hum
 
Solution: (1) Use a single-phase power supply for the audio system and another single-phase power supply for the lighting system
 
           (2) The power supply of the audio system adopts an isolation transformer, and the power of the isolation transformer should be greater than the power used by the audio system
 
 
 
7. The effect of singing sound is small and not full enough
 
 
 
Cause of the failure: It may only use the single-channel effect sound of the effect machine, or not connect the two-in-two-out of the effect machine
 
Solution: Generally, the effect machine has left and right channel input and left and right channel output, try to connect in this way
 
 
 
8. The effect of singing voice is not added
 
 
 
The reason for the failure: the singing sound does not enter the effect machine
 
Solution: Turn on the corresponding auxiliary knob on the singing channel, turn on the auxiliary knob sent by the auxiliary bus, and observe the input signal indicator of the effect machine to see if there is an input signal
 
Failure reason: The effect sound sent by the effect machine is not programmed into the left and right channel bus or group bus
 
Solution: Press the button programmed into the corresponding bus
 
Failure reason: the effect machine is damaged
 
Solution: Replace the effect machine
 
 
 
9. The microphone is inserted into the mixer without sound signal
 
 
 
Cause of failure: poor contact of the microphone switch, the microphone switch is not turned on, or the microphone is damaged
 
Solution: Check the microphone cable, turn on the microphone switch or replace the microphone
 
 
 
10. Hold the stage wired microphone, make a slight swing, and the sound reinforcement box makes a "click" sound
 
 
 
Failure reason: poor contact of microphone switch
 
Solution: replace the microphone switch, or re-weld the switch wiring
 
The cause of the fault: the microphone terminal is disconnected, or the shielded wire is in contact with the signal wire
 
Solution: Disassemble the XLR plug socket, weld the disconnected wire firmly, separate the shielded wire from the signal wire clearly, and weld firmly
 
 
 
11. Unbalanced sound from left and right channel speakers
 
 
 
Failure reason: the sensitivity of the left and right channel speakers is not the same
 
Solution: Adjust the output level of each channel of the left and right channels to make the sound of the speakers close to the same
 
Failure reason: unbalanced output power signal of left and right channels
 
Solution: Adjust the device input level of each channel to approximately the same indication
 
 
 
12. When the single-channel microphone is connected, the volume is louder. When the two microphones are connected, the volume decreases
 
 
 
The cause of the failure: the signals of the two microphones input to the mixer are reversed
 
Solution: If each input of the mixer is equipped with an inverting button, press one of the two microphone inputs. If each input of the mixer is not equipped with an inverting button, switch one of the microphone signals Weld the wire, and then weld it firmly
 
 
 
13. After the wireless microphone is turned on, there is no sound when speaking into the microphone
 
 
 
The cause of the failure: the battery on the wireless microphone is insufficient
 
Solution: Replace with new battery
 
Cause of failure: the tuner volume is not turned on
 
Solution: Turn on the tuner volume switch and exceed 3/5
 
Cause of failure: The angle of the tuner receiving antenna is not adjusted properly
 
Solution: Change the receiving angle of the tuner antenna to avoid blind spots in the host's activity area
 
 
 
14. The left and right channel speakers are split type, and the sound of each channel is uneven
 
 
 
Cause of failure: The crossover point of the two-channel electronic crossover is not adjusted properly
 
Solution: According to the use of the frequency divider, carefully adjust the crossover frequency points of the high and low ends
 
 
 
15. The left and right channels of the sound source have output, and there is no sound signal output after entering the mixer
 
 
 
The cause of the failure: the constant value attenuation button of the corresponding input channel on the mixer is pressed
 
Solution: pop up the constant attenuation key of the corresponding channel on the mixer
 
Cause of failure: The gain adjustment on the corresponding channel is placed in the lowest position
 
Solution: Turn on the gain adjustment of the corresponding channel and place it on the 2/3 position
 
The cause of the failure: the placement of the panning knob on the corresponding channel is opposite to the input left and right channel signals
 
Solution: The position of the sound image adjustment knob on the corresponding channel is consistent with the input left and right channel signals
 
Cause of failure: The plug of the input mixer is in poor contact or disconnected
 
Solution: Check the input plug and solder it firmly
 
Cause of failure: poor contact or desoldering of the output of the mixer
 
Solution: Check the output plug of the mixer, connect it correctly, and solder it firmly
 
Cause of failure: The input signal is not programmed into the corresponding output bus
 
Solution: Press the programming button of the corresponding output
 
 
 
16. The sound source is reproduced, and the speakers of the sound reinforcement system are silent
 
 
 
The cause of the fault: there is no sound signal output from the sound source, or there is a short circuit or open circuit in the output plug socket of the sound source device
 
Solution: repair or replace the sound source equipment. Carefully check the sound source in the wiring and plug socket to eliminate short circuit or open circuit
 
The cause of the failure: there is an open circuit or a short circuit in the connection line between the devices
 
Solution: carefully check the connection status of the wiring and plugs and sockets of each device, and eliminate false soldering, desoldering and short-circuiting
 
Cause of failure: One or more of the power switches of the serially connected equipment are not turned on, and the acoustic signal is interrupted
 
Solution: turn on the power of the audio equipment
 
The cause of the failure: the sound source button of the input channel of the mixer is misplaced
 
Solution: correctly place the sound source switch button
 
 
 
17. One of the left and right channel speakers has no tweeter (tweeter)
 
 
 
The cause of the failure: the tweeter of the speaker is overloaded and burned
 
Solution: swap the two input signals of the power amplifier. If the tweeter of the speaker still has no tweeter, it means that the tweeter is burned out and the voice coil should be replaced.

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