nominal Impedance 8 ohms, minimum 4 ohms .Recommended Amplifiers : 15 to 250 watts .Frequency Response : 25hz to 30Khz .Sensitivity :91db linear for 1 watt at 1 metre .Bass/Midrange :2 x 165mm (6 1/2") ProAc unit with carbon filled polypropylene cone, anti-resonant dust cap, raised spider for greater linearity and large shielded magnet assembly. Tweeter : ProAc 25mm (1") direct radiating silk dome. Crossover :HQ network using the finest components with option for bi-amping/bi-wiring and utilising oxygen free cable. Terminals : Response type high quality terminals. Dimensions : 41" (1040mm) high on plinth and spikes.7,5" (190mm) wide.11" (280mm) deep .Weight : 20kg each with spikes and plinths .Mode : Floor standing with spikes .Grille : Acoustically transparent crimplene .Finish : Available in the following real wood veneers: Black Ash, Mahogany, Cherry, Maple.