Polk Audio RM75 5-Channel Home Theater System (Set of Five, Black) 5-piece 5-channel home theater system Includes 4 RM7 satellites, 1 RM7 center channel Over all frequency response: 95Hz-22kHz Heavy-duty, non-resonant composite enclosures Magnetically shielded for safe placement next to today's state-of-the-art TVs and monitors