we're using 3" speakers because that particular cone has the best qualities for our room, which happens to be quite large. the mains are tuned to 60hz. this creates a flat response all the way through to 50hz, which then becomes subwoofer territory. of course this is all being done on paper, so real life results will naturally be different. the goal for me and my father's project is to build an HT that is astounding, aesthetically pleasing, and looks like $$$$$$$$$, but costs $$. i'm selling my DD and i'll sell the dayton. my dad is going to buy my PE 1000w amp for 325 off of me, so that way i can get a good 700 or so to make a new room setup.