Right now i have my 2 12'' SExxx's in a sealed box. I have the oportunity to buy a subzone z series vented box for cheap and its new. The specs are 1.5 cubes per sub and its tuned to 38 hz. I heard 2 12'' H2's in this same model box and they were loud. Would it be noticable louder then my sealed box? The only thing i am worried about is the 1.5 cubes per sub.