Extra deep well design with a Cassini oval woofer mounted above and behind the main driver & tweeter array, for broad coverage and dynamic full-range audio performance in a built-in. Vanishing® Series built-in speakers feature our exclusive wafer-thin Sheer-Grille™, a magnetically-secured grille that protrudes only 7mm from its surroundings. Sheer-Grilles have nearly transparent, ultra-small perfs, and are acoustically inert, for dynamic, unimpeded sound and more uniform coverage, even in larger rooms. Painted to match your décor, Vanishing Series built-in speakers are virtually indistinguishable from their surroundings. Enhanced, reengineered ring radiator tweeters extend top-end response for incredible details and realistic imaging. Reflective surfaces in rooms can make sound brighter and cause image distortion. Engaging the Vanishing reflective room compensation feature (by selecting the low setting) lowers the tweeter level to compensate for reflective surfaces. Vanishing reflective room compensation is a custom audio control that cuts the level only in the 4-5kHz range, exactly where reflectivity destroys sound quality. Outside this narrow 1kHz band, the tweeter retains its detailed and accurate high frequency response, for no loss of realistic musical details. Vanishing Series LS speakers are timbre-matched to Polk LSi speakers to insure utterly seamless blending from speaker to speaker in systems that combine traditional and built-in speakers.