Polk Audio MC60 High Performance In-Ceiling Speaker Specially tuned for excellent ambient performance, with superb detail and natural musicality, even at low volume Easy one-cut, drop-in installation puts built-in audio within reach, with Perfect Fit templates, a precision flange and (available) pre-construction brackets; achieve secure, vibration-free efficiency with a simple turn of the patented Rotating Cam system Lightweight and stiff polymer drivers provide excellent damping and bass response Aimable swivel tweeters for greater accuracy and more realistic imaging Polk's proprietary, patented Dynamic Balance technology allows engineers to design out distortion-causing driver and system resonances, so you only hear the good sounds