Audiocontrol Three.2 Car Audio EQ 4 Band Equalizer 24db Crossover Aux 13 Volts

And just for fun, you can set the knob illumination color to hot red or cool blue. 3-band EQ: +/-12 dB at 125, 1,250, and 10,000 Hz. Para-BASS EQ: +/-12 dB at 40-80 Hz. Preamp/Equalizer and Subwoofer crossover.