SpeakerCraft's Whole House Audio in-wall and in-ceiling speakers offer high performance and great appearance at a surprisingly affordable price. Every model uses components usually found only in architectural speakers costing considerably more. 6-1/2" Polypropylene Cone Woofer with Polyurethane Surround 1/2" Liquid Cooled Polyamide Dome Tweeter Efficiency: 87dB 1W/1m Power Recommendations: 5 - 40 watts (undistorted) Impedance: 8 OHMS Frequency Response: 60Hz - 19kHz Wall Cut-Out: H 10-3/4" x W 6-3/4" Dimensions: 12 3/16" H x 8 3/16" W x 3 7/8" D