DS18 DNA-1800.2 DNA Series 1800 Watts Max Two-Channel Stereo Amplifier Extruded Aluminum Chassis, Black, Glossy, and Polished Heat sink with MOSFET PSU Transistors. Fully Regulated PMW Power Supply, Hi/Low/Pass Outputs, 200mV-5V Low Level Inputs, Direct 4 GA. Power Terminals, and 8GA. Speaker Terminals. 2-Ohm Stable in Stereo Mode, 4-Ohm Bridged Stable Class A/B, with RMS @ 4-Ohms of 2 x 250 Watts, RMS @ 2-Ohms of 2 x 400 Watts, and RMS @ 4-Ohms of 1 bridged x 660 Watts. Crossover and Switching: Variable Hi Pass 50 Hz - 400 Hz, Variable Low Pass 50 Hz - 400 Hz, Bass Boost at 0-6-12 dB at 45 Hz. THD 90dB. Frequency Response 10 Hz- 50 KHz. Tri-Mode Capability, Power and Diagnostics LED's, Unbalanced Inputs (RCA's), Full Range Outputs (RCA's), Variable Input Level Control. Four Way Protection Circuit: Thermal Protection, Over-Load Current Protection, Output Direct Current Protection, Speaker Short Circuit Protection.