Rockford Fosgate Punch Series P500-1bd 500w RMS Monoblock Amplifier Mono amplifier with 200W x 1 @ 4-Ohms, 400W x 1 @ 2-Ohms RMS, 500W x 1 @ 1-Ohm RMS Variable low-pass crossover (35-250Hz 24dB/octave Butterworth) Variable bass boost (0dB to +18dB @ 45Hz) and infrasonic filter (-3dB @ 28Hz 12dB/Octave) Class-bd amplifier with MOSFET output stage and power supply Audiophile grade speaker connections and RCA pass-thru