Polk Audio Blackstone TL1 Speaker Center Channel with Time Lens Technology | Compact Size, High Performance, Powerful Bass | Hi-Gloss Blackstone Finish | Create your own Home Entertainment SystemCREATES A SOUNDSTAGE COMPARABLE TO ANY LARGE SYSTEM. Features two (2) 2. 5 inches drivers, a 0. 5 inches silk dome tweeter & injection molded cones. The APERIODIC TUNED REAR PORT delivers bass extension and boosts the audio on a shelf or mounted against the wall UNIQUE CURVED SHAPE BASED ON "TIME LENS TECHNOLOGY" It is specially designed to align the acoustic centers of the tweeter and mid bass in the same plane, reducing diffraction & distortions,