well i wont say much as most of the members have already said alot. but just for the sake of it, u need to sum a number of calculations to make a good box if not perfect, let alone the port area required n the length. btw to clear the fog of alot of people, port length and its area is NOT determined by the sub, but the box ur making.
Though i may not be fully satisfied with the TSP's features and its purposes, but yes to some extent. TSP's are NOTHING more than just numbers to satisfy ur emotions.
They tend to change every millimeter when the sub plays and i dont have to tell anyone what a sub does when its played. only some of the TSP's are useful such as Bl, xmech with xmax etc which helps u in making decisions rather than a stupid program which needs it and YOU DONT KNOW WHY.lol..
If i was dependent upon any box programs, i would have a 16cft of an enclosure dat too with a 38+ tuning.
If anyone really wana learn about enclosures, DO IT MANUALLY, as in by several steps of calculations..
As for the company's recommendations, they do so for naive and an average user who doesnt know what to do. And the other reason is they want their product to last long no matter if its satisfying the customer needs or not. Thirdly, most of the companies are over rated, they dont want u to play it on its full capacity. Most of the manufacturers know the impedance and coil rise of the box and the sub they are recommending and selling so your sub is actually seeing far less then wat the numbers show.
As again, too many variables to count for lol
Thanks
Riz