Windows-based computer : Windows® XP, Windows Vista® or Windows® 7, PC sound card or 3.5 mm audio output jack, Mac® computer : Mac OS® X 10.3.9 or later, Package Contents : 2 satellites, 1 subwoofer, Control pod, User documentation, Technical Specifications : Total RMS power: 25 watts, Peak power: 50 watts, Frequency response: 48 Hz–20 kHz (+/- 3dB), Dimensions (W x L x H): Subwoofer: 8.6 inches by 5.9 inches by 9 inches (22.0 cm by 15.0 cm by 22.8 cm ), Satellites: 3.2 inches by 3.5 inches by 5.75 inches (8.1 cm by 8.9 cm by 14.6 cm )