Sony XM-GS100 GS Series Class D Subwoofer Amplifier Compact chassis size 330W x 1 RMS at 4 Ohms 600W x 1 max power at 4 Ohm 600W x 1 RMS at 2 Ohms 1100W x 1 max power at 2 Ohm GS Series and 3-year warranty