Generally speaking, computer stereos 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.
Electromagnetic interference is mainly divided into power transformer interference and stray electromagnetic interference. Generally speaking, the interference of power transformer is caused by the leakage of multimedia speakers. If there are conditions, the effect of installing a shielding cover on the transformer is very obvious, 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.
Stray electromagnetic interference is very common, and speaker cables, 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.
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.
It should also be noted that if the potentiometer is used for a long time, the metal brush will have poor contact with the diaphragm due to dust accumulation and wear, and noise will be generated when it rotates. 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. The reason for this situation may be that the output power of the power amplifier is small, which can not avoid the large dynamic peak signal at the moment of music, or the loudspeaker is overloaded and distorted.
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