Which box is better for Brahma?

Ok, so Would it be louder for me to build a 2 cu. ft. box and give the brahmas 1500+ each or a 4.5 cu. ft. box with about 8-900 watts each? Cause from what Im hearing they are about the same when all said and done. Thanks for the help guys

go ported if you want it loud... I personally like the larger boxes for the subs, better lows...