REAudio SA90.4 800W 4-Channel SA Series Full Digital Amplifier SA Series 4-Channel Full Class Car Amplifier RMS Power Rating: 4 ohms: 63 watts x 4 chan. / 2 ohms: 85 watts x 4 chan. / Bridged, 4 ohms: 151 watts x 2 chan. Max power output: 800 watts 4 or 2 channel operation Speaker-level (high-level) inputs with signal sensing for automatic turn-on