Elac BS72 Bookshelf Speakers- Black Satin (Pair) 2-Way, Bassreflex Bookshelf Design - Frequency Response from 56 28,000 Hz-Recommended Power Range: 20-100 Watts per Channel Nominal Impedance: 4 &#x3A9; Sensitivity: 86 dB / 2.83 V / 1 m