Ok here's where i'm stuck at, 4 15's or 3 18's, i got 24 to 25 cu ft to work with before displacement walled with double mdf top, bottom, back and sides while the baffle will be 3 or 4 layers of mdf.. after displacement it will sit between 16 to 21 cu ft.. which way would you go?? don't worry about subs and power, i got that taken care of... I know 3 18's has more cone area and will move more air..