Generally speaking, speakers are mostly active speakers, and there must be a power amplifier inside, so noise is inevitable. The noise of active speakers can be roughly divided into electromagnetic interference, mechanical noise and thermal noise according to their sources.
Speaker problems can cause:
I. Electromagnetic interference
Electromagnetic interference can be divided into power transformer interference and stray electromagnetic interference.
1, power transformer interference
Due to the magnetic leakage of multimedia speaker power supply, it is very obvious to add a shielding cover to the transformer when conditions permit, which can block the magnetic leakage to the greatest extent. The shield can only be made of iron-based materials. Try to choose products with big brands and solid materials. In addition, using an external transformer is also a good solution.
2. Stray electromagnetic interference
More commonly, speaker wires, frequency dividers, wireless devices or computer hosts will all become interference sources. The main speaker should be as far away from the computer host as possible to reduce the surrounding wireless devices.
Second, the mechanical noise
Mechanical noise is unique to active speakers. In the working process of power transformer, the vibration of iron core caused by alternating magnetic field will produce mechanical noise, which is very similar to the hum of fluorescent lamp ballast. Choosing good quality products is still the best way to prevent this noise. In addition, we can install a rubber damping layer between the transformer and the fixed plate.
Third, thermal noise.
When the potentiometer is used for a long time, the metal brush and the diaphragm will be in poor contact due to dust accumulation and wear, and noise will be generated when rotating. If the screws of the speaker are not tightened, the inverter tube is not handled properly, and mechanical noise will also be generated when playing large dynamic music.
This thermal noise can be dealt with by replacing low-noise components or reducing the workload of components. In addition, lowering the working temperature is also one of the effective methods.
In addition, some computer speakers, when the volume is too large, will also appear noise. This situation is because the output power of the power amplifier may be relatively small, which can't avoid the large dynamic peak signal at the moment of music, or because there are many situations that will cause the noise of the speaker, such as the speaker being disturbed, the interface or connecting cable being in poor contact, and the quality of the speaker itself is poor.
Other problems lead to:
1, incorrect card insertion.
The sound card is not closely separated from the expansion slot of the motherboard. Visually, the "golden finger" on the sound card is misaligned with the reed of the expansion slot. This phenomenon exists in both ISA card and PCI card, which is a common problem. We can solve this problem by inserting the sound card correctly.
2. The input end of the active speaker is connected to the speaker output end of the sound card.
The active speaker should be connected to the Line-Out end of the sound card, and its output signal is not amplified on the sound card, so the noise is much less. Some sound cards only need one output. Whether it is Line-Out or Speaker depends on the jumper on the card. The acquiescence mode is often Speaker, so you have to unplug the sound card and adjust the jumper when necessary.
3, sound card driver problems
You can use the driver that comes with the system, or there is something wrong with the driver. If so, you can change the sound card driver.
If other factors are excluded, it is the speaker himself. Suggest a replacement.
Supplement: Then exchange the goods.