The Role of a Power Amplifier in a Car Audio System

Music is an everyday part of life, especially while driving. This fact is because most working adults only have time to listen to music in the car before rushing home. So it is no wonder people are installing subwoofer speaker systems in their vehicles. In a car the subwoofer speaker system contains three basic components; speakers, subwoofers, and amplifier. The power amplifier is one of the best parts of this system.

What is a power amplifier and what does it do?

The power amplifier is part of a subwoofer speaker system. It is named solely on the power it outputs. It sends an “amplified” signal to the loudspeakers to give it the bass sound. An amplifiers main purpose is to take a weak signal and make it strong enough to drive the loudspeaker.

With a subwoofer speaker system, the power amplifier works on and input and output basis. There are three stages power supply stage, input stage, and output stage. When learning about or dealing with these stages you will come to see a lot of technical jargon that can be hard for some to understand.

The power supply stage deals with powering the power amplifier. This happens by taking 120 Volts Alternating Currents (VAC) and converting it to Direct Currents (DC). An easy way to understand this is that your amplifier will convert the power coming in so that it is usable.

The input stage deals with taking the input signal and preparing it for output. When dealing the input stage it is best to have a balanced input as it helps with noise reduction versus single ended input.

The output stage is the most important as it is the stage that actually amplifies the weaker signal to the speakers. This stage is where the most transition occurs, thus producing the heat you feel after the amp has been on too long.

Power Amplifier Classes

Class A amplifiers are the second most commonly used class of amplifiers in a vehicle. They have a low distortion, meaning the distortion lessens the lower the volume is. Unfortunately this class of amplifiers is highly inefficient, using up power even when there is no music coming through the speaker.

Class B amplifiers are a cost effective approach to a subwoofer speaker system. They provide a much higher amount of efficiency, unfortunately it entails enduring more distortion when dealing with a low signal level.

Class C amplifiers are never used in any audio systems, especially vehicles. The reason for this is there is way too much distortion to provide any quality sound in an audio circuit.

Class D amplifiers are in a wide range of car audio subwoofer speaker systems due to the efficiency, quality, and cost. They have been around for a long time, but up until recently they weren’t used as often.

In layman’s terms the role of the power amplifier in your car is that is boosts or amplifies the signal to your speakers, allowing for a stronger sound. When looking to install a subwoofer speaker system in your car, you always want to have a power amplifier to give the boosted sound. The safest bet is to go with a Class D Amp or a Class A as a second choice.