Philips HTS3111. Audio output channels: 5.1, RMS rated power: 100 W. Satellite speaker impedance: 4 Ом. Center speaker impedance: 4 Ом, Center speaker tweeter size: 38.1 mm (1.5 "). Subwoofer type: Passive, Subwoofer frequency range: 20 - 150 Hz, Subwoofer impedance: 3 Ом. Subwoofer weight: 3810 g