need box help for treo ssx 18s

[greg4510]

hey guys i have a 2007 tahoe im running 2 treo ssx 18s on 2 mmats 3000.1 i got some info from the forum before on a box build. what im going to build is about a 13 1/2 cu. ft. with a 150 sq in port box tuned at 32hz. my question is what would be better sounding subs facing up and port backwards or both facing backwards? its a daily driver and i listen to rap and r&b so im looking for which would give me the best output