The fault symptoms of the sound reinforcement system, the causes and solutions are shown below.

(1): The sound reinforcement system plays no sound

The power plug of one or more of the audio equipment connected in series is not plugged in. Solution: Check the power terminal block so that the socket is in good contact.

(2): The sound reinforcement system sometimes makes a "click" sound, especially in the process of playing music, this phenomenon constantly occurs.

(1) There is virtual welding phenomenon in the connection line between the equipment of the sound reinforcement system. When there is a music signal, the virtual solder joint makes the acoustic signal intermittent solution:

(2) The wiring of each channel equipment must be thoroughly checked, and it is best to re-weld each connection point;

(3) If the connection solder joints are thoroughly inspected, the "click" phenomenon still occurs, it may be that the connecting wire is broken, check each wire with a multimeter, and replace the cable with broken wires inside.

(3): When the sound reinforcement system is silent, the AC sound is serious

1. The connection shielding wire of each channel equipment is in poor contact or virtual welding, the solution: carefully check the shielded wire between the equipment, and try to use welding.

2. The device with a three-pin power plug is connected to the socket of the second-wire input, and the second-level live wire is reversed from the neutral wire, Solution: The second-wire input socket, the neutral wire and the live wire must be reversed. Generally, the left foot of the socket is a neutral wire, and the right foot is a live wire. The power strip should be equipped with three pins, and the upper middle pin should be connected to the earth wire to ensure the safety of electricity.

3. Some audio equipment adopts two-pin plug, but some equipment must use three-pin plug, otherwise AC induction phenomenon may occur when connected, leading to AC sound solution: turn the power plug of the two-pin plug of the audio equipment upside down.

(4): When the sound system and the lighting system are running at the same time, the AC noise of the sound system is very large, and after the lighting system is turned off, the AC sound cannot be heard when the sound system is running. The sound system and the lighting system share the same single-phase electricity. The thyristor of the lighting system has a large operating current and is AC pulsed, which is directly coupled to the input of the expansion device through the power supply lead, resulting in a large AC sound solution:

(1) The sound system and the lighting system are independently powered;

(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 of the audio system;

(5): During the sound reinforcement process, a group of speakers or two groups of speakers at the mouth of the left and right channels suddenly become silent;

Under normal circumstances, it is due to the overload of the power amplifier or the burning of the speaker under too much sound power Solution:

(1) Replace the amplifier or speaker;

(2) Replace the special-shaped paired high-power transistors to repair the power amplifier, we must pay attention to the occurrence of this situation, which is caused by overload, and great attention should be paid to operational problems when tuning. In order to protect the amplifier or speaker, the sound reinforcement system can consider adding a limiter;

(6): In the karaoke hall, the singer's singing voice is separated from the musical accompaniment played and does not merge.

1. The left and right channels of the audio source enter the mixer, and the acoustic image adjustment button on the corresponding channel is placed indiscriminately, resulting in chaotic sound and image, Solution: correct the adjustment of the corresponding channel acoustic image adjustment button, so that the output signal of the mixer retains the sound image of the original sound source;

2. The room equalizer only compensates for the sound of music, or the room equalizer room equalization curve is not adjusted reasonably, the solution: readjust the room equalization compensation curve;

(7): The effect processing of the singing voice is not added

1. The singing voice does not enter the effect machine, solution: open the corresponding auxiliary knob on the singing sound channel, open the auxiliary knob sent by the auxiliary busbar, and observe the input signal indicator of the effect machine to see if there is an input signal.

2. 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 to program the corresponding bus bar.

3. The effect machine is damaged, the solution: replace the effect machine.

(8): The effect sound in the singing voice is small and not full enough

It may only use the single-channel effect sound of the effect machine, or it may not be connected according to the effect machine two-in-two-out Solution: Generally, the effect machine has left and right channel input and left and right channel output, try to connect it in this way.

(9): The sound source plays sound, and the sound reinforcement system speaker is silent

1. There is no output sound signal from the sound source, or there is a short circuit or open circuit in the output plug and socket of the sound source device.

Solution: Repair the sound source device or replace the sound source device. Carefully check the sound source in the wiring and plug socket to rule out short or open circuits.

2. There is an open circuit or short circuit in the connection line between each equipment Solution: carefully check the connection status of the wiring of each equipment and the plug and socket, and exclude virtual soldering, desoldering and short connection.

3. One or more power switches of the serial equipment are not turned on, and the sound signal is interrupted Solution: Turn on the power of the audio equipment.

4. The sound source button of the mixer input channel is misplaced Solution: Correctly place the sound source switch button.

(10): The microphone is plugged into the mixer without a sound signal

Poor contact of the microphone switch, microphone switch not turned on, or microphone damage Solution: Check the microphone cable, connect the microphone switch or replace the microphone.

(11): Holding the stage wired microphone, with a slight swinging action, the sound reinforcement box makes a "click" sound.

1. The microphone switch is in poor contact, the solution: replace the microphone switch, or re-solder the switch wiring.

2. The microphone terminal is disconnected, or there is a shielding wire meeting the signal line Solution: Disassemble the XLR plug holder, weld the wire firmly, the shielded wire and the signal line are clearly separated, and the welding is firm.

(12): When the single microphone is turned on, the volume is louder. When the two microphones are switched on, the volume decreases and the signals from the two microphones input to the mixer are inverted.