Kenwood KAC-8404 600-Watt Max Power Stereo Four-Channel Power Amplifier with Variable LPF/HPF 4-channel car amplifier 50 watts RMS x 4 at 4 ohms (75 watts x 4 at 2 ohms) 180 watts RMS x 2 bridged output at 4 ohms (4 ohm stable in bridged mode) high-pass (12 dB per octave) and low-pass (24 dB per octave) filters variable from 50 to 200 Hz variable bass boost (0-18 dB at 40 Hz)