Amplifier units are the device which amplifies the sounds to the user requirements. In other words an Amplifier helps in reproducing the sound at a higher volume without distortion. The main functions of an Amp or an Amplifier is to increase the volume of the signals sent through the speakers. It's job is to not only increase the volume of the signals, but also reduce the distortion or any kind of crackling. There are different variants of Car Amplifiers available on the markets from a 2 channel system to 5 channel audio systems. All these categories of channels are meant to satisfy user different requirements when listing to music.