Kenwood KAC-X4R Excelon Four-Channel Digital Power Amplifier 1200 Watts Max Power 75 Watts X4 @ 4 Ohms, 100 Watts x4 @ 2 Ohms Dimensions in inches: W:13.3/D:8.8/H:2.3 Variable Infrasonic Filter: 15~60Hz -24db/oct Dual Power Supply