Kenwood KAC-9104D 1800-Watt Max Power 1 ohm Capability Class D Mono Power Amplifier with Variable LPF Mono subwoofer amplifier 500 watts RMS x 1 at 4 ohms (900 watts x 1 at 2 ohms) Variable low-pass filter (50-200 Hz at 24 dB per octave) Bass boost (0-18 dB at 40 Hz ) Subsonic filter (15/25 Hz, 18 dB/octave )