The head unit is the main control device for a car audio system. Head units are generally installed in the center of the dashboard or dash panel. Among the most common mobile audio components are in dash car stereo receivers in single DIN or double DIN housings and primarily with an AM-FM tuner. Today, many car stereo receivers have modern features such as video LCD screen, multimedia DVD playback, Bluetooth hands free, XM Sirius satellite capability, iPod hook ups and more.
The headunit or deck, is the main focal point of any car audio system. It is considered a key component, as it is the foundation of any good sound system. Many newer radios have control for multiple amplifiers with internal subwoofer and fader controls. High end units incorporate digital parametric EQ's and offer streaming audio services such as Pandora.