Kenwood KAC-6104D 600 Watt Max Power Class D Mono Power Amplifier with Variable LPF Mono subwoofer amplifier 200 watts RMS x 1 at 4 ohms (300 watts x 1 at 2 ohms) Variable low-pass filter (50-200 Hz, 12 dB per octave) Preamp- and speaker-level inputs