I've been researching subwoofers for a couple of months now, and am ready to pull the trigger on one. I'm down to three, eD A5-350 (w/ 550w amp), Hsu VTF3-MK3 and the Epik Knight. All are approx. the same price once shipping is included. My room (after recalculation) is 4500 cu. ft. I'll be using it for 50/50 music/HT. The sub will be joining a pair of Polk RTi10's and a CSi5 center and replacing a Polk PSW404 sub. All comments and suggestions on these selections will be appreciated and will greatly help me with my decision.