WinISD is a great program that uses a speakers T/S parameters to help you design the perfect box for your speakers.  This works on any type of speaker that does not have a built-in enclosure,  You just need to find the T/S specs for the speakers.  The best part, it allows you to model, sealed, ported, bandpass and even passive radiator systems.  In fact, it will recommend a box size and type based off the T/S specs.  It really is a must have for speaker and subwoofer builders/ designers.  If you are unsure of how to use the program or what the T/S specs are.  I recommend you check out these video tutorials to begin with:

The entire playlist can be found here: WinISD Tutorials