The SX-1800 produces 1800 Watts of power from a class AB amplifier design. The SX-1800 lets you run a system at 600-Watts per-side in stereo mode with out breaking a sweat, thanks to the internal amplifier design and variable-speed fan cooling. FEATURES:[ Professional Class AB Power Amplifier[ 400 Watts per side @ 8 Ohms[ 600 Watts per side @ 4 Ohms[ Dual Variable-speed Fan Cooling System [ Signal, Peak, and Protection Circuit Indicators[ 5-way Binding Post and Speakon Speaker Outputs[ XLR and TRS Input connections[ Dual Rack Space Design ";