Tuning the audio system can be as critical as tuning the fuel map in an ECU when trying to squeeze more power from the motor. The Autotek 7007 Half-DIN 4-Band 2-Way Equalizer/Crossover can be installed up front for quick control of master and sub volume along with equalization for real time tuning that is critical if your system will be playing many styles and genres of music. It is perfect for add-on MPS players and has a built-in 9V line driver. Plus the selectable blue or red illumination adds a cool glow to the front.