Im building a ported sub box for two 12"Dcon D4's.im in to SQ more than SPL, witch would be better a 3.2ft^3 iternal volume tuned to 30hz with 45.in^2 port area. or a 4.0 ft^3 internal volume tuned to 30hz with 60.in^2port area? im new to building ported boxes so any help would be a help...lol... thanks,,,,,,PS im runing a RF T500-1dbcp