Speaker maintenance and fault analysis

For most users, there are no special requirements for the use of multimedia speakers. Due to unfamiliarity with the product structure and lack of relevant knowledge, many users often use the speakers as is after a minor fault occurs, and replace them if it really doesn't work. In fact, many faults of multimedia speakers are very simple to repair and ordinary users can easily solve them.

As a durable consumer product, speakers are not prone to failure, but once a problem occurs, it will make you very upset and bring us a lot of inconvenience. Be prepared for a rainy day and do a good job of maintenance and care during daily use of speakers, which can at least delay the life of the speakers and make your use more comfortable.

Today we will learn about the daily maintenance methods of speakers:

Speakers are an important part of the entire audio system, and their value accounts for about half of the entire system, so they must be treated properly.

① Avoid placing it in places exposed to direct sunlight, near heat radiation appliances such as stoves, heating pipes, etc., and avoid placing it in humid places.

② Before connecting the speakers to the amplifier, the power supply of the amplifier should be cut off to avoid damaging the speakers.

③ The feeder connection to the amplifier should be secure, not fall off when pulled, and the positive and negative polarities should not be connected incorrectly. The feeder connecting the speaker should be thick enough and not too long to avoid loss and damping deterioration. The maximum deviation from the frequency response is ±0.5dB (the maximum length of 0.75mm2 wire is 9cm, the maximum length of 1.5mm2 wire is 14m, and the maximum length of 2.0mm2 wire is 21m.

④ Pay attention to whether the speaker impedance is suitable for the recommended value of the amplifier

⑤Do not use it beyond the rated power. Otherwise the sound quality will deteriorate or even damage the speaker.

⑥ The outer shell should be wiped with a soft, dry cotton cloth. Do not apply furniture wax or benzene or alcohol.

⑦The dust on the surface of the speaker can only be removed with a soft-bristled brush, not a vacuum cleaner.

⑧The speakers should be placed on a solid, firm floor to prevent bass attenuation. Do not place the speakers too close to the wall.

⑨ Do not place the speakers too close to the turntable to avoid acoustic feedback and howling.

⑩ If there is mid-range and treble level adjustment, it can be adjusted according to listening requirements to make the sound satisfactory.

Speaker System Fault Analysis

The speaker system is one of the important components of audio equipment, usually composed of speakers, crossovers, cabinets, sound-absorbing materials, etc. The failure rate of the speaker system is low, and the types of failures are few. Common failures are divided into the following four categories.

1. Silence

1. The speaker wiring is broken or the crossover is abnormal. When the speaker wiring is broken, the speaker unit has no excitation voltage, which will cause a silent fault. The crossover is generally not easy to break, but the lead joint may be desoldered, the crossover capacitor is short-circuited, and other faults may occur.

2. The voice coil is broken. You can use the multimeter R×1 to measure the lead wire soldering piece of the speaker. If the resistance is ∞, you can use a knife to scrape off the sealing paint of the lead wires at both ends of the voice coil to expose the bare copper wire and then measure again. If it is still not connected, it means that the voice coil is broken; if the measurement is connected and there is a "clicking" sound, it means that the voice coil lead wire is broken. You can solder the wire head and then use another section of enameled wire similar to the voice coil winding to solder it.

3. The speaker lead wire is broken. Due to the frequent vibration of the speaker cone, the braided wire is easy to break. Sometimes the wire is broken, but the cotton core wire remains connected. This braided wire is not easy to buy, so it can be replaced with a slightly longer soft wire.

4. The voice coil is burnt. Use the multimeter R×1 to measure the speaker lead. If the resistance is close to 0Ω and there is no "clicking" sound, it means that the voice coil is burnt. Before replacing the voice coil, you should first clear the debris in the magnetic gap, then carefully put the new voice coil into the magnetic gap, straighten the voice coil, and use super glue to fix the upper and lower positions of the voice coil while listening. After the voice coil is in the best position, use super glue to fill the gap between the voice coil and the paper cone to about half, and finally seal the dust cover, put the speaker paper cone upward, and leave it for one day before normal use.

2. The sound is intermittent

1. The speaker lead is bad. Usually it is caused by the voice coil lead being broken or poorly welded. When the paper cone vibrates frequently, the breakpoint is sometimes connected and sometimes disconnected, resulting in irregular sound and sometimes no sound.

2. The voice coil lead is broken or about to short-circuit.

3. The power amplifier output jack has poor contact or the speaker input cable is broken.

3. Low volume

1. Poor speaker performance, magnetism of the magnet decreases. The sensitivity of the speaker mainly depends on the magnetism of the permanent magnet, the quality of the paper cone and the quality of the assembly process. You can use a ferromagnetic object to touch the magnet and roughly estimate the strength of the magnetism based on the size of the attraction. If the magnetism is too weak, you can only replace the speaker.

2. The magnetic core is loose. When the magnetic core of the speaker is loose, it will be sucked to one side by the magnetic plate, causing the voice coil to be squeezed and hindering normal sound. When inspecting, you can press the paper cone lightly with your hand. If it does not move, it may be that the voice coil is pressed by the core, and it needs to be disassembled and re-glued before it can be restored to use.

3. The crossover is abnormal. When there is a defective component in the crossover, the signal of the corresponding frequency band is blocked, and the speaker in this frequency band has a low volume fault. You should focus on checking whether the crossover capacitor connected in parallel with the woofer is short-circuited, and whether the crossover inductor coil connected in parallel with the tweeter is short-circuited between layers.

4. Abnormal sound

1. There are foreign objects in the magnetic gap. If there are foreign objects in the magnetic gap, the voice coil will rub against the foreign objects when it vibrates, causing the sound to be hoarse.

2. Voice coil rubbing against the core. The voice coil is not in the correct position and rubs against the magnetic core, causing sound distortion. During maintenance, the voice coil position should be corrected or replaced.

3. The paper cone is broken. If the damaged area is large, the paper cone should be replaced. If the damaged area is small, it can be repaired with a thinner paper cone or other paper with better toughness.

4. The box is bad. If the box is not sealed well or the decorative grille is not installed firmly, it will cause cracking sound during playback. In addition, if the box plate is too thin, it will cause resonance and abnormal sound.