I have two kickers cvr 12" on a sealed box dual voice coil 4 ohms and i want to get a cvx 15" and i want to know if a kicker cvx 15" will hit more than the two cvrs and what kind of box will be better for the cvx sealed or ported. Does it going to be a big difference going from two 12 cvrs to a 15 cvx. 400 rms for each cvr. 1000 rms for the cvx.