Bookshelf Hi-Fi Speakers, Frequency Response (±3db): 79 Hz - 28 kHz, Amplifier Power: 40-100W, Nominal Impedance: 8 Ω (min. 3.5 Ω), Sensitivity: 85dB, Dimensions Per Speaker: 302 x 200 x 280.5 mm (11.9 x 7.9 x 11.0 in.), Weight: 7.8kg