Why do some speakers get very loud with just a slight turn of the volume? What is the relationship between volume and potentiometers? What are the differences between an A10K potentiometer and a B100K potentiometer?
High signal impedance means high signal voltage and low signal current. Here, a high-value potentiometer with a large K number should be used. If a low-value potentiometer with a small K number is used, the signal voltage will be significantly reduced, which can cause distortion.
Low signal impedance means low signal voltage and high signal current. In this case, a low K-value potentiometer should be used, as using a high K-value potentiometer would cause distortion when the low-voltage signal passes through the high K-value resistor.
Potentiometers are used with a higher K-value in areas with weak signals and a lower K-value in areas with strong signals. The angle of twist required to achieve a certain volume level is not significantly related to the potentiometer's K-value, but rather to the voltage division ratio of the potentiometer and is more related to the A-type or B-type. Volume adjustment should be done using the A-type potentiometer.
If a potentiometer's adjustment rotation angle is 300 degrees, dividing 300 degrees into 20 equal parts results in 15 degrees.
Type A: The initial few divisions have minimal resistance changes, forming a small adjustment zone. As the twist angle increases, the resistance change per division also increases, adapting to the human ear's sensitivity to sound perception. Resistance changes of a 50K Type A step potentiometer: 49.9Ω, 75Ω, 100Ω, 220Ω, 340Ω, 470Ω, 604Ω, 750Ω, 1.1K, 1.5K, 2.2K, 3.3K, 5.1K, 6.04k, 6.04k, 6.49k, 5.49k, 4.7k, 3.3k, 2.4k
Type B: Each equal division of the twist angle has the same resistance value. A 50K potentiometer divided into 20 equal parts results in a resistance change of 2.5K per division (equivalent to the 11th division of the volume in Type A). This is characterized by a significant sound change with just a slight turn of the potentiometer.
