The Boss Audio R1004 400W 4 Channel Power Amplifier Amp (2 Pack) features a MAX power handling of 400 watts and a RMS power handling of 50 watts. The Class A/B circuit design run cooler and more efficiently with low distortion and high reliability. This class is intermediate between Class A and B, with the two active elements conducting more than half of the time which are best used for speakers. Other features include a Hi/Low pass crossover, a variable bass boost and is 2 ohm stable. Trimode Capable 2 Ohm Stable Signal to Noise Ratio: >95 dB