Alpine's ERE-G180 1/2-DIN graphic equalizer offers exceptional system control in a compact package. In addition to 11 bands of equalization, the unit boasts high-pass and low-pass crossovers, three sets of preamp outputs, subwoofer level control, subwoofer phase switch, and a handy input level indicator. The built-in BBE sound processor adds clarity and power to your music by adjusting phase relationships and pumping up bass response.