Harman Kardon HKTS 11 5.1 Home Theater Speaker System - Black Lacquer Finish Box Contents - 4 Satellite Speaker, Center Speaker, Subwoofer, Wall-mount brackets for satellite speakersSystem Frequency Response (-6dB) - 35Hz - 20kHz Satellite Recommended Amplifier Power Range - 10 - 120 watts Impedance - 8 ohms nominal Sensitivity - 86dB @ 1 watt/1 meter