ok so the box has a reccomended size of: Ported: 51ltrs (1.8 cu. ft.) 33hz tuning
so the box should be 51 ltrs, plus the area of the magnets, plus 2 or 3 litres, plus the area of the port?
Im going to make up a couple of ports, this shouldnt matter greatly?
Aldo just just so i understand the area of the port does not belong to the box, like the air in the port is not part of the 51 ltr volume of the box?