I am making a ported fiberglass box, and I wanted to know how I go about doing the port, when I dont know the exact internal volume until the box is made???
its quite complex and you will need to determine the volume b4 you build, if your doing a basic 2 side mdf and the rest glass, you will need to use the 2/3 rule which is how much volume you have inside compared to if that box was fully mdf, the fiberglass box would only be 2/3 the actual volume over mdf
or you could build the box, find the volume, then use areo ports cut to the desired length for the ports