The major component of a Car`s Radio system http://www.autoradio-1001.com/de/ is the head unit for it performs a whole lot of activities. An audio system generally requires three to four parts at the initial stages of the signals which are then transferred to the amplifiers and then to the speakers to produce the sound or tune in a refined form. But since a car has limited space and all these had to be fit in it, the head unit was developed which performs all these functions as a single unit. Apart from this, they also perform some tone controlling activities like treble and bass to refine the music signals before they reach the customer`s ears. Some systems also come with a woofer and sub woofer controlled by the head unit.