Hifonics COLOSSUS Classic Mono subwoofer audio amplifier delivers 4200 watts with Super D Class technology that features Ultra-Fi MOSFET outputs that are selected for both balance and output power. Low Noise Preamplifier CircuitMaximum low voltage signal from the source unit comes into the amplifier circuit with minimal distortion.. RCA InputsNickel-plated RCA jacks create the most efficient High/Low Level audio connection and resist corrosion.. Operation ModeMono only. Crossover TypeVariable electronic crossovers allow for complete control of the sound. Electronic EqualizerControl of amplifier output with on-board electronic crossover to tailor specific frequencies to speakers and subwoofers. Class / TopologySuper D-Class? designs which employ high-speed microprocessors with proprietary D/A conversion algorithms to efficiently control the current consumption. At very high listening levels, Hifonics amplifiers with Super D-Class circuitry result in lower distortion, higher current efficiencies and less heat than conventional D-Class amplifier designs. Output Device TechnologyPro-Fi? Output Device Technology: The Ultra-Fi? MOSFET is designed for music production vs just electronics output power. It produces very musical high power with high efficiency for cooling and minimal distortion.. Heat SinkHeavy-duty aluminum alloy heat sink efficiently moves heat from the MOSFET for superior dissipation.. Power SupplyThe dual coil Pulse Width Modulated power supply keeps voltage constant through the Ultra-Fi output devices. Output ConnectionsHigh temperature impact resistant nickel plated connectors with allen head set screws which allow for secure termination of wire and creates an erosion resistant seal.. Connection TypeSecure molded connection terminal for all Power, Ground and Speaker connections. Angled for ease of access while creating a clean wire mangement profile.