Soundstream MPQ-90 1/2-DIN Car Audio 9-Band Graphic Equalizer Subwoofer Control.

SOUNDSTREAM MPQ-90. Front, Rear, & Subwoofer RCA Outputs. Variable 60Hz-90Hz Subwoofer Low Pass Crossover. Nine Frequency Bands with 18db Boost/Cut Frequency Response: 10Hz-15kHz. THD: 0.05%. S/N Ratio: 115dB.

eBay