STUDIO 630 6.5" 2-way Compression Driver Bookshelf Loudspeaker, 6.5" (165mm) PolyPlas Low-Frequency Woofer, High Definition Imaging (HDI) Waveguide with 1” (25mm) High Frequency Compression Driver, Recommended Amplifier Power: Max 150W, Frequency Response: 45 Hz - 40 kHz, Sensitivity: 85 dB, Nominal Impedance: 6 Ohms, Enclosure Type: Bass-Reflex via Rear-Firing Tuned Port, Dimensions (W x D x H): 230 x 280 x 372 mm, Weight: 9.02 kg