STUDIO 620 5.25" 2-way Compression Driver Bookshelf Loudspeaker, 5.25" (133mm) PolyPlas Low-Frequency Woofer, High Definition Imaging (HDI) Waveguide with 1”(25mm) High Frequency Compression Driver, Recommended Amplifier Power: Max 100W, Frequency Response: 50 Hz - 40 kHz, Sensitivity: 84 dB, Nominal Impedance: 6 Ohms, Enclosure Type: Bass-Reflex via Rear-Firing Tuned Port, Dimensions (W x D x H): 190 x 240 x 312 mm, Weight: 6.88 kg