Im Trying to design some ported reflex cabs around some second hand PDN2151 drivers. Can I chop the dimensions win ISD has given me for 2 square ports in half and use the same length to create 4 triangle ports. also I presume I add the total port areas to the box volume i have chosen or does win ISD already do that. Thanks to any one that can advise me, I would hate to build some shoddy sounding cabs