The Hifonics HFEQ is a half-DIN, ISO mounting 4-band, 9-Volt line-driver preamp EQ with front/rear active crossover features and extensive subwoofer crossover controls. The HFEQ's "Line Driver" circuit delivers a whooping 9-Volts of preamp level signal through the RCA's. Any consumer wishing to get the most out of their add-on amps and subwoofer system needs the HFEQ. The HFEQ's small 1/2 DIN size permits many mounting locations. All non-in-dash installs will find the Hifonics HFEQ's small-size chassis handy to install. Especially into center / overhead consoles, glove boxes or in any 1/2 DIN pocket opening.