Polk Audio MM 572 Mobile Monitor Series 5"x7" 2-Way Car/Marine Speakers (Pair) This speaker for car and marine use, the Polk Audio MM572 5" x 7" 2-Way Coaxial, is a flagship Mobile Monitor series model designed to easily handle extreme conditions. This speaker features 300W peak power, a titanium-plated composite woofer cone that can also be used in 6" x 8" application, Terylene fabric tweeter, and a Santoprene rubber surround. Polk's proprietary Dynamic Balance technology ensures a distortion-f