Polk Audio RTI A5 Floorstanding Speaker (Single, Cherry) Single real wood floorstanding speaker with all MDF construction and resonance-free enclosures Equipped with dual 6.5-inch dynamic balance mineral/polymer composite cone drivers Features Power Port technology to reduce "chuffing" or "port noise" Equipped with one 1-inch silk/polymer composite dome tweeter Features a neodynium magnet, low viscosity ferro-fluid cooling, and a heat sink on the back of the magnet