ZD-750.4D

The Hifonics ZD-750.4D is a compact ZEUS DELTA four channel amplifier rated at 750W max power. It delivers 4 x 100W into 4 ohms, 4 x 175W into 2 ohms, and bridges to 2 x 375W into 4 ohms, which is the right range for waking up factory door speakers or running a set of aftermarket coaxials and components front and rear.

The chassis is the story here: 7.32 x 5.75 x 2.16 in and 3.13 lb, small enough to mount under a seat, behind a kick panel, or in the spare tire well of a compact car. Class-D topology and an aluminum heat sink keep it running cool in enclosed mounting spots.

Variable high-pass and low-pass crossovers each sweep 50Hz to 250Hz at 12dB per octave. High-pass the front stage so door speakers stop straining on low bass, or low-pass a bridged pair feeding a small subwoofer. Response runs 10Hz to 22kHz with THD under 0.5%, built-in bass control shapes the low end, and input sensitivity from 0.2V to 6V matches factory or aftermarket sources. Speaker-level inputs allow a tie-in to a factory head unit with no line output converter.

Angled molded terminals take 4 AWG power and ground and 12 AWG speaker wire for a clean wiring profile in tight spaces. Nickel-plated RCA inputs resist corrosion, end-panel LEDs flag overload and speaker shorts, and DC Signal Sense starts the amplifier on RCA signal. External 60A fusing required.