Logitech Z533 - speaker system - for PC  Product Type Speaker system - for PC - 2.1-channel  System Components 2 speakers, subwoofer  Speaker Type Active  Nominal Output Power (Total) 60 Watt  Frequency Response 55 - 20000 Hz  Amplifier Integrated  Speaker System Details 2 x satellite speaker 15 Watt 8 Ohm | 1 x subwoofer 30 Watt 4 Ohm  Power AC 120/230 V (50/60 Hz)