buck

Ok first off I know kicker isn't the best but this is what I have,and wanted to get the best from wha I have with out taking all the space up in a Cadi EXT. 2- kicker L715 2 ohm 2-jL 1000 w sub amp Width max is 4' and I want to tune it to 33hz with slotted Ports,what cubic ft you guys suggest...