Polk Audio SurroundBar 50 Surround System Speaker (Single, Black) Single magnetically shielded surround bar speaker with neodymium motor structures for safe placement on or near TVs Equipped with nine 3.5-inch composite cone drivers Contains dual front ports for superior clean, low distortion bass Equipped with three 0.75-inch silk/polymer composite dome tweeters Polk Audio's patented SDA Surround Technology delivers a vivid sound field from a single 51-inch cabinet