Polk Audio RM6750 5.1 Channel Home Theater Speaker System (Set of Six, Titanium) Six piece surround sound package that includes 2 front and 2 surround speakers Satellite and center-channel speakers utilize 3.25-inch polymer-composite cone drivers Features 0.5-inch silk and polymer-composite dome tweeter in each satellite speakers Subwoofer utilizes an eight-inch long-throw dynamic-balance poly-composite driver Satellite and center-channel speakers can accommodate 6.1 or 7.1 channel systems