Kenwood Excelon KAC-X10D Mono subwoofer amplifier 600 watts RMS x 1 at 2 ohms mono subwoofer amplifier 300 watts RMS x 1 at 4 ohms (600 watts RMS x 1 at 2 ohms) Dual Sigma Drive eliminates acoustic resonances variable low-pass filter (40-200 Hz, -24 dB/octave) switchable infrasonic filter (15/25 Hz, -24 dB/octave)