Professional audio system failure analysis and troubleshooting

Currently, there are many types of professional audio equipment. Inevitably, there will be various errors when using so many devices. Some are faults of the device itself (hard failures), and some are man-made failures caused by improper use (soft failures). In general, the failure of the audio system can be summarized into five categories: power failure, line failure, human-machine failure, equipment failure, and interference failure. Our main components today are power failures, line failures, and manual operation failures!

Summarize the system power failures

The overall power configuration of the audio system is important and requires the following considerations:

1. Three-phase electricity

In general, where professional audio equipment is used will be suitable for installing a three-phase power supply. What's more, two independent three-phase power supplies can also be used. If one of them fails, the entire system will not be paralyzed; Even very important houses use backup power, such as the computer's "UPS", which shows how important power is.

2. Separate audio and lighting power

It is better to have a separate power supply for the sound system and lighting, otherwise one is prone to interference, and the other is unsafe to work.

3. Total power distribution

It is not enough to have a powerful power supply. Pay attention to power distribution: in principle, mixers and various audio devices must have independent power supplies; Various peripheral devices must have independent power supplies; Power amplifiers and other devices must have at least one independent power supply. 2 independent power supplies. Each independent power supply is controlled by a corresponding air switch, so we are very convenient for switchgear.

 

 

Device sub-power failure

The power failure of the device itself can also be divided into 3 parts:

1. The internal circuit part of the device is faulty

Our ordinary sound engineers cannot rule it, we need professional maintenance personnel or equipment suppliers to guarantee it.

2. There is a problem with the power supply of the device

For example, some DC-powered devices require the use of transformers, and sometimes transformers will fail; There is also a problem with the power cord that connects the device, but it rarely happens, but really good power cords look good, but they do not turn on. and replace the power cord when the fault is eliminated.

3. There is a problem with the plug-in device

For example, there is a problem with the socket and power sequencer connected to the device. The probability of this failure is relatively high, especially when performing mobile performance.

The power supply voltage is stable, and the plug-in device is faulty

Nowadays, electricity consumption in various industries is increasing, so it is difficult to ensure that the voltage of the power supply is within a constant standard range. In this case, many places where audio is used are equipped with power processing equipment, such as voltage stabilizers for audio systems. But when choosing a device, you must pay attention to the quality of the stabilized power supply and voltage stabilizer; In some places, the quality of the power outlet or power sequencer is relatively poor and also prone to failure.

Power system failure conditions

1. When a ballroom is newly opened, when debugging the sound system during the day, the voltage is normal and the system is normal, but when performing performance, it does not work at night. Voltages as low as 180 volts and some sound devices do not work properly. This place uses three phases of power, one relative to the sound system, one phase relative to the lighting system and air conditioning system, and one phase of the lighting system elsewhere. When the sound is adjusted during the day, the lights and air conditioning in the ballroom are not turned on, so the power is normal, but different at night. The three-phase power supply is unbalanced, and the problem arises. Later, the air conditioning system also used single-phase electricity alone, and the status lighting system used a civilian power system to balance the three-phase power and solve the problem.

2. When a ballroom performs in the ballroom, the speaker always emits a \ "click" sound, and it turns out that the quality of the voltage stabilizer used is not very good. Whenever the voltage stabilizer pointer of the voltage stabilizer, the speaker will make a \ "click" sound later after replacing the transformer, and I find that sometimes there is a power pulse sound. As a result, I found that whenever I pressed the stage camera console, the sound was noisy. Later, the power supply of this controller was simply plugged into a civilian power outlet. Resolves an issue with separation from the main power supply in the mixer.

From the above example, we know that the power supply is causing several types of failures and that we must rely on our careful installation, configuration and use. Therefore, the power supply components are very critical and important.

 

 

Audio system wiring failed

(1) Power cord failure

There are many places where the power supply is used in the sound system, and various power cables are required to connect, such as: the power supply of mixers and audio players, the power supply of peripheral equipment, the power amplifier power supply, the stage power supply, the active speaker power supply, the video system power supply, etc., so the power connection cable must be safe and reliable, and try to avoid failure.

(2) Signal line failure

If you compare the sound system to someone, then the signal connection lines of the sound system are like human blood vessels. "Blood circulation" directly affects the stability of the sound system, but even if you know that the signal line is so important, it can malfunction. In summary, there are the following types of failures:

1. The quality of the signal line itself

This malfunction is the most irritating. When this kind of problem happens, we can only naturally scold the blasphemer, on the other hand we have to do everything we can to re-release that line, which is really frustrating.

2. During installation, the signal cable is damaged

Sometimes we use high-quality cables, there is no problem checking before installation, but there are problems after installation. This can be caused by damage to the signal cable during installation, especially for some long-distance transmission cables. During installation, sliding the wire too hard when threading the pipe may cause damage to the wire; Accidental damage may also occur during construction of other types of work; The wires can also be bitten by the tooth grinding function of mice. In any case, there are various reasons for failure, so it tries to spare as many spare parts as possible.

3. Signal line welding problem

When welding signal lines, attention should be paid to the welding quality of each solder joint, and the other is that various signal lines and their corresponding various plugs should be connected correctly. For example, XLR XLR connectors have 1, 2, 3 and 3 This connection should not be confused, so after the signal line is soldered, check it with a multimeter to see if it is shorted or disconnected.

 

 

 

The connection cable between the power amplifier and the speaker is faulty

Everyone should pay more attention to the connection between the power amplifier and the speaker. They will use good quality and thicker speaker cables. When they fail, the speaker cable is usually short-circuited. The speaker connections are now all four-pin plugs. If TS6.35 plugs are used, the risk of short circuits in such plugs will be greatly increased; Speaker wires are usually rarely broken. If the thick wire is broken, it is usually man-made and the wire itself is unlikely to be a problem.

Line system failure cases

When a company built a multipurpose hall for a customs house, the stage was about 80 meters from the sound control room, and 8 microphones were needed on the stage. As a result, when all 8 microphones are turned on, the noise in the speakers is as loud as rain, and it is impossible to accept it. Later, it was decided to cut off the TS6.35 unbalanced plugs of all conference condenser microphones and change all to XLR XLR plugs, all using balanced transmission mode. As a result, after 8 balanced transmissions from the microphone, in normal volume, at 2 meters from the speaker, there is basically no noticeable noise. The same signal cable, but the result is very different, so we must pay attention to it. Failure caused by signal line.