First things first. I'm not going to tell you what to do, I'm only sharing my experience. I have a trunk, sealed enclosures are the worst thing you can do in a trunk. I don't know where you are getting this idea that they sound better, or that the response is flatter, or whatever the fukc you think, but be open to suggestions before you ask questions. I have a FI BL 15" in 4cubes tuned to 32hz....sounds great, from high 20s to 50s output is pretty good. the rear deck starts going ape **** around 50, the higher end of the substage holds up well, plus if you get good front stage you won't have much to worry about. If you did 1 15 ported, it would be great, but if you did like 2-3 10s, it would sound great as well brotha, but the whole using a sealed enclosure is a defnite no no, plus those q-logic aren't the best regardless. Next thing, why are you leaving amp gain all the way down, but turning the eq 50hz all the way up?? that makes no sense. you're not giving yourself any head room at your finger tips. That's kind of the point of having the eq up front brother. Your subs are getting stinky because you're clipping the shti out of them when you misuse that eq...I mean do what you want, but shti! I have a eqs746, they're great and made everything sound that much better, but **** man!!....eff the sealed box, go 2 10's ported, or put a nice 15" ported in like 3.5 cubes man....you'll be very pleased with the consequences of following suggestions. That is exactly what I did, listend to what these fukcs said and my **** sounds great