PIONEER GM-6500F Gm Series 4-Channel 60-Watt X 4 Bridgeable Amplifier • 760W Max • 4 Channel • 60W X 4 • 180W X 2 Bridged @ 4_ • 85W X 4 @ 2_ • Freq Resp: 10 Hz - 70 Hz • Thd: <0.05% • Variable Lpf/Hpf • Variable Crossover