Welcome to our store Learn more

New collections added! Learn more

Flash Sale Now ON!



What about class d amplifier ?

YuanYuan Liu |

What about Class D Amplifier?


If you have an amplifier in your car, then you must be concerned about which class is most suitable for car audio. So what’s amplifier class? Let’s learn from this article.


car amp


Class A amplifier to class D amplifier


Of all amplifier classes, only four are commonly used car sound systems, one of which is a combination. The four amplifier classes are class A, class B, class AB, and class D amplifier . Here’s a quick primer on these amplifier categories.

Basically, there are only two kinds of power amplifiers, analog and switch. These basic types are further subdivided into a dozen letter classes. Some (such as T and Z) are proprietary trademark designs, while others (such as class d amplifier ) are manufactured by a variety of manufacturers.


Class A Amplifier: It’s clean output, high fidelity, low distortion, but large, creates a lot of heat.


Class A amplifier is always on by definition. It uses an inner circuit designed to pass current through the output transistor at all times. The pros and cons of this basic design make the Class A amplifier suitable for some applications rather than others. In a car stereo, the biggest problem of class A amplifiers is size.


Class B Amplifier: It’s efficient, has a smaller size and creates less heat, but lower audio fidelity and potential signal distortion.


Class B Amplifier is different from class A amplifier, they are switched. This means it uses inner circuitry that effectively turns off the output transistor when no audio signal needs to be amplified. This increases efficiency and makes the Class B amplifier ideal for car stereo, but also reduces audio fidelity.


car sepaker


Class A/B Amplifier: It’s more efficient than class A​; less distortion than class B, but less efficient than class B and more distortion than class A.


This kind of amplifier is a hybrid of the traditional A and B amplifier classes. Although the transistor has a current flowing through all the time, the circuits they use can reduce the amount of current flowing when there is no signal. This results in higher efficiency than a pure class A amplifier without the same distortion as a class B amplifier. Because of these advantages, Class A/B power amplifier is the most commonly used full-frequency amplifier in car stereo system.


class D amplifier: It’s extremely efficient, but distortion at high frequencies.

Class A, B, and AB amplifiers are examples of analog amplifier classes, making Class D the only commonly used switch amplifier class in automotive audio systems. Different from other amplifier classes, class D amplifier operate by turning the transistor’s current on and off very quickly. Although class D amplifier  are very efficient, the switch/pulse method results in a certain degree of distortion at higher frequencies. Many single-channel subwoofer amplifiers are class D amplifier , but size and power advantages make them one of the more popular types of amplifiers for full-frequency speakers.


car stereo system


Which Amplifier Class is the Best?


If you want to listen to a good sound without going too deep, the basic rule of thumb is that A/B amplifiers are best for full-frequency and most component speakers. But class D amplifier are better for driving subwoofers.