Does the potentiometer determine the size of the sound

Some friends buy stereos. Compared with the sound effects of the two stereos, they are usually fooled by the business. The business will turn the volume potentiometers of the two stereos to a certain position, such as the middle position. People are used to the position of the hour hand of the clock. The comparison is called turning on until 12 o'clock, and then listening to whose volume is louder, it will be judged whose power is louder. In fact, this is completely misleading, because this method of comparison often results in the opposite of reality, and may even be used by illegal businesses or manufacturers to get you into a trap. So what is wrong with this method of judgment? The potentiometer plays a decisive role in the sound volume, do you know this?

On this issue, you may be misled by two delusions. First, the illusion caused by the size of the machine's gain. Second, the illusion caused by the characteristics of the potentiometer. The characteristics of the potentiometer will be explained below.

Does the quality of the potentiometer determine the size of the sound? In fact, the linearity of the potentiometer plays a decisive role.

The potentiometer is a component that changes the signal strength. The process of rotating the potentiometer actually changes the attenuation coefficient. The minimum position is 0 and the maximum position is 1. However, the attenuation coefficient corresponding to a certain position in the rotation process is not the same for every potentiometer. For example, when it is turned to a half position, the attenuation coefficient is not all 0.5. If the attenuation coefficient is half by half, and the attenuation coefficient for 1/4 is 1/4, this potentiometer is called a linear potentiometer. However, people have long discovered that the human ear’s perception of volume is not linear. When the signal is attenuated by half, it doesn’t sound like a half. In order to make this attenuation process in line with the characteristics of human hearing, There is a potentiometer called exponential characteristic. The exponential characteristic shows the attenuation characteristic that is slow first and then fast, but because it offsets the non-linearity of the human hearing, it makes the hearing feel uniform. Therefore, in the classic circuit design theory, the volume potentiometer uses exponential characteristics. If you use a linear potentiometer as a volume potentiometer, it will feel loud when the volume is turned on a little bit. In the dead of night, there is no way to get a lower volume, which makes it difficult to control the volume. This is because the machine reaches the maximum power it can output too quickly. In fact, it is very limited to increase the power output of the machine, and it is even distorted.

As for the exponential potentiometer mentioned above, compared with the linear potentiometer mentioned above, the volume will feel low at the same position, but there is no need to worry about the loss of the maximum output power.