I have a friend who "years ago" had a set of "roadkill" 8's. he was running them full range off the deck.....(he has no clue when it comes to this stuff no matter how many times I tell him) anyway, he had this favorite song that sounded"amazing" on that one set up, and he has heard my system and believe me it sounds OUTSTANDING, but that one song still doesnt sound "good"to him. if your friend really thinks SQ subs are run full range he needs a shrink, and a kick in the nuts. As far as the Diamond TDX's are concerned you can pick them up from Woofers etc. for $309 each for 10's. If you can get the W7 for cheaper go for it otherwise I'd say try the Diamonds. I've had JL's, Fosgates, Kickers, Orions, MTX, all kinds of stuff, I'm completely sold on the Diamonds, The SQ on them is Amazing, I listen to all kinds of stuff, from Jazz-Hard core Metal-Hip Hop-female vocalists-techno. Try 'em out you wont be dissappointed. I PROMISE!!!!!! //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif good luck