i belive what he was saying is that he made a ring to mount the sub too to give it more clearance and that doesn't mean that it leaks air. I personally have 2 12" jbls under my back seat and have plent of airspace they only need like .6 cu ft and my box is .75 and i would also have to agree with what has been said before it depends on what sound you like as to what speaker is right for you, i've has Jl, Kicker, Eclipse, Diamond, and now i have jbl, its not always whats the best or the loudest, its what works best for you and how much you can afford, i'm sure eveyone would love to have top of the line equipment that would just blow you away but its not practical for everyday use.