USB 2.1CH SPEAKERS: Subwoofer: Drive Unit: 4"x 1 Output Power: 6W x 1 Frequency: 60HZ-300HZ Impedance: 4 Ohm Sensitivity: 89 dB THD: <0.1% Material: ABS Plastic Dimension: 149.9x207.4x183.9mm Satellite: Drive Units: Full Range 2"x 1 Frequency: 250HZ-20KHZ Impedance: 4 Ohm Sensitivity: 90 dB THD: <0.1% Material: ABS Plastic Dimension: 133.7x118.8x95.8mm