Hifonics Zeus ZXI6410 340 Watt A/B Class Four-Channel Amplifier 4 x 85 W @ 4 Ohms, 4 x 170 W @ 2 Ohms, 2 x 340 W @ 4 Ohms Bass EQ with 45Hz bass boost and variable control from 0db to 10db; Variable Low Pass, High Pass/Subsonic Filter, Phase Shift and Level Control Crossover Selector for easy High Pass, Full Range or Low Pass operation Built-in system diagnostics protects from short circuits, over load, thermal over-heat and DC offset