Ask for help computer amplifier stereo, there is a slight sound! What to do?

The meaning of sensitivity is that when a voltage of 1V is added to the speaker, the sound pressure value obtained by a person at a distance of 1 meter.

Sensitivity (unit: dB dB): The sensitivity of the speaker refers to the sound pressure level measured at a distance of 1m from the geometric center of each speaker unit on the front of the speaker when the input electrical power to the speaker in the speaker system is 1W (the sound pressure is proportional to the amplitude and frequency of the sound wave, and the sound pressure level is an indicator of the relative magnitude of the sound pressure).

It should be pointed out here that:Although sensitivity is an indicator of the speaker,But it has nothing to do with sound quality、Timbre,It only affects the loudness of the speaker,You can increase the input power to improve the loudness of the speaker。

Frequency response (unit: dB dB): refers to the constant voltage output of the audio signal and the speaker system connection, when changing the frequency of the audio signal, the sound pressure generated by the speaker increases with the change of frequency or attenuation and phase lag changes with the frequency of the phenomenon, the sound pressure and phase and the corresponding change of frequency relationship is called frequency response.

The curve of sound pressure with frequency is called the "amplitude-frequency characteristic", and the curve of the phase lag with frequency is called the "phase frequency characteristic", and the combination of the two is called "frequency response" or "frequency characteristic". The amount of change is expressed in decibels. This index is an important indicator to evaluate the quality of the speaker,The smaller the decibel value,The flatter the frequency response curve of the speaker,The smaller the distortion。

The signal-to-noise ratio, also known as signal-to-noise ratio, is the contrast between the strength of the useful components of the signal and the noise, and is often expressed by the number of decibels. The higher the signal-to-noise ratio of a device, the less noise it produces. For ***** devices, the signal-to-noise ratio is a relatively important parameter, which refers to the ratio between the maximum undistorted sound signal intensity and the noise intensity emitted at the same time by the sound source, which is called the signal-to-noise ratio, referred to as signal-to-noise ratio (signal-to-noise ratio), usually expressed in S n, and the unit is decibels (dB).

A higher signal-to-noise ratio indicates a better product.

Is it that the sound card is not installed?

There are the following reasons why the amplifier sound is loud:

1. If it is a heavy metal iron impact, it is caused by the engine fixing frame due to long-term severe wear;

2. If it is a humming sound, it is caused by the loosening of a part;

3. If it is a scream, it is a failure of the air conditioner or cooling system of Changxi;

4. If it is a heavy knocking sound, it is caused by engine aging or damage to bearings or engine valves.

Solution: 1. Replace the original parts of noise and aging in Lichang;

2. Reduce the working temperature;

3. Find a professional repair shop to repair the loose limbs and quickly pick up the original.

When the mid-to-low-end speaker is not sensitive to liquid, there will be various noises: if there is a low-frequency hum, it is the communication sound; If there is a high-frequency squeak, it is the high-frequency noise of the transistor; There is a slight sound like running water, which is the interference sound of switching power supply.

Of course, there is a way to deal with it, I have worked in Shenzhen Meishengda Electronics for many years, mainly responsible for the development of the eggplant burial work, and the improved circuit will no longer tremble and touch this noise.

The reason for the interference sound of the switching power supply is that the input impedance is too high, and the problem can be solved by reducing the input impedance. Specifically, a resistor and capacitor are connected in parallel at the signal input to suppress this noise. The improved frequency response is theoretically worse and in practice there will be no noticeable difference.