I have 2 05' s12L7D4's in a 4.2cu ft ported box at 37 hz. I would like to have better SQ out of my setup and was wondering if I should get different subs or just make a new box thats tuned lower and try to get better SQ. I want it to be at least really close to as loud as it is now but sound better. I have looked at these subs and would like your opinion on them vs my L7's. SS Rl-p and RE SX. Would 1 15' or 2 12's of these be more of what I need?Thanx