Polk Reserve R400 Powerful Center Channel Speaker for Immersive Audio Performance. Polk's Reserve R400 Center-Channel Speaker is a high-performance loudspeaker that delivers ultra-clear and crisp highs, smooth and detailed midrange, and effortless bass. It features a 1" Pinnacle Ring Radiator Tweeter and dual 6.5" Turbine Cone Woofers with Hi-Res Audio Certification, Dolby Atmos, and IMAX Enhanced support to produce high-quality sound with pure detail. Whether you're listening to music, watching movies, or playing video games, the R400's bass reflex cabinet with a rear-firing port and Polk's Patented X-Port Technology with Eigentone Filter (ETF) ensures tight, distortion-free bass for an immersive audio experience. The premium, large 5-way binding posts ensure an easy, efficient setup with a lossless connection. Place this powerful center speaker on a stand, shelf, tabletop, or any flat surface, or mount it on the wall using integrated rubber feet. Pair with two R200 bookshelf speakers, and two R700 tower speakers or with two R350s as L/R surrounds, and add an R900 height module for depth (all sold separately) to create a multichannel surround sound system. The R400 is compatible with the latest file formats like DSD, FLAC, WAV, ALAC, and MQA, so you can experience superior audio performance at home.