Polk Audio TL2600 Speaker System (Set of Six, Black) Time Lens Technology-The acoustic centers of the tweeter and mid-bass driver are located in the same plane for superior imaging PowerPort a patented Polk technology, extends the low frequency mid-bass driver response as it decreases air turbulence, 3/4" Silk Dome Tweeters for crisp, clear imaging and smooth response that's never tiring. 3 1/4" Composite Injection Molded Cones With Dynamic Balance Driver Technology Downward Firing Powered Subwoofer. A compact vented enclosure with an 8" long-throw Dynamic Balance poly composite driver. Eliminates "port noise" and bass output losses up to 3 dB.