Pioneer 40WX4 480W Peak Power Amplifier GMA4604 GM Series 4-Channel Class AB Car Amplifier RMS Power Rating: 4 ohms: 40 watts x 4 chan. & 2 ohms: 60 watts x 4 chan. & Bridged, 4 ohms: 120 watts x 2 chan. Max power output: 240 watts x 2 chan. Variable Bass Boost (0 to +12 dB bass boost at 50 Hz) 4/3/2 or Mono channel operation