Mirage OMDR Black Ea OMNIPOLAR Rear Surround Speaker Recommended Amplifier Power: 25-200 Watts (Unclipped) Impedance: 6 Ohms Nominal/4 Ohms Minimum Tweeter: Two 1-Inch Titanium Domes Midrange: Two 2-Inch Chambered Titanium Cones Woofer: Two 5.25-Inch Multi-Layer Carbon Fiber with Underhung Motor Systems