Where does the speaker noise (background noise) come from and how to eliminate it?

Where does the speaker noise (background noise) come from and how to eliminate it?

Definition of noise

There are many types of noise, and the causes are different and the performance is different. Therefore, it is necessary to classify the noise. The following is a classification of the common noise in several audio equipment, and a brief description of the causes and solutions.
01White Noise
White noise is a kind of random noise in the full frequency domain. It sounds like an endless "sizzle" sound, similar to the sound when the TV has no signal to play.

White noise is usually generated by the gain device or power amplifier in the device. If the volume is adjusted too high, it is easy to produce a significant background noise. At this time, you need to check the output volume of the sound card, software and speakers to ensure that no overload is generated in each link.

PS: High-sensitivity microphones, such as condenser microphones, can pick up noises that are almost inaudible to the human ear in the room environment, such as air conditioning, outdoor noise, and wind noise. Don't ignore the influence of environmental noise when recording.
02 digital distortion
Digital distortion often makes a harsh "buzzing" sound, which does not sound like the sound in nature. Generally speaking, it will vary according to the process used by the computer. For example, when using different software or effects, digital distortion will also change.

Digital distortion is generally caused by some problems with the sound card, or when the monitor speakers and the computer are connected to the same socket. Make sure that the power supply of your monitor speakers or other playback equipment (such as monitor controller) and other digital devices such as computers are connected to independent power outlets. Or use a reliable power adapter.
03 Feedback Howling
Feedback is usually due to the microphone being too close to the speaker, and the microphone will pick up the sound of the speaker and self-excitation occurs. At this time, there will be a harsh high-frequency howling. When watching some small bands perform tuning, howling often occurs.

Put on headphones instead of monitor speakers for recording when recording, so that the microphone will not pick up the speaker sound and self-excited. When using headphones when performing or playing without conditions, you can move away from the speaker and adjust the microphone gain.
04 crackling murmur
These sounds can usually be divided into the following two types:
One is the random crackle distribution, the most likely cause is the software parameter setting. Increase the cache size should be able to get it.
The second is a rhythmic crackling sound, such as a crackling sound every half a second, which may be caused by damaged sound card or the driver is not installed correctly.

Such crackling noises are often caused by incompatible software or drivers of the sound card. For example, the Buffer Size is set too low, Bluetooth or wireless devices are connected to the system, or the software compatibility is poor. You can check the content of the software compatibility of the sound card on the official website to see if your computer does not meet the minimum requirements for the sound card.

If this type of noise is heard from your speakers, you can try unplugging the speakers and connecting them to headphones to determine where the noise is coming from.