The Lsif/x Is The Perfect Complement To The Line Of Ultra High Performance Polk Audio Lsi Front Main Bookshelf And Floorstanding Loudspeakers. With Them, You Can Build The Ultimate Polk Audio Multi-channel Music And Cinema Sound System. To Get Exceptional Lifelike Performance From Your Multi-channel Audio System, You Need A Center Channel Speaker And Surround Speakers With The Same Sonic Characteristics As The Rest Of Your Speakers. The Aerated Polypropylene Cones And Ring Radiator Tweeters In The Lsif/x Speakers Are The Same Components Used Throughout The Lsi Series. This Produces A Seamless Front Stage And Lifelike Surround Environment. Lsif/x Surround F/x Speakers Envelop You In Sound. They Are Built Especially For Today's Discrete Multi-channel Digital Formats, Timbre Matched With The Complete Lsi Series For An Utterly Realistic Surround Experience. Switchable Bipole/dipole Operation Gives You More Performance And Placement Flexibility.