Hola amigo! @tlsguy is a wizard and has designed/built many speakers. He’s also very generous with his knowledge, and maybe he’ll drop in her. I know he’s very busy atm.
Anyways, as the warrior indicated, to simply equal the output it can take as many as 4 sealed boxes. I am personally not a fan, and I believe mark(tlsguy) has voiced his dislike as well.
Despite that, more to your question.
IMO, FS is a quick indication of a drivers intended purpose. Higher FS of say, 30hz would indicate a sub that isn’t meant for HT FS since it’s very difficult to get a sub to play below its FS without dis too, and without pushing it to death. Output in a sealed application takes a lot of power and a lot of excursion. And when you start to EQ the bottom end to increase output, it will quickly introduce distortion, and power requirements This and all the extra excursion creates heat, and is very bad for driver parts. Other T/S parameters I don’t remember so much off hand, but the ones(qts?) that refer to a high or low Q, are important to note, as that will indicate a one note wonder, or a linear controlled bass source. Hopefully someone can elaborate as I just haven’t had my mind there for awhile.
Also, ported subs aren’t that much more difficult(academically at least) to build than sealed, and given your hands on approach, and seemingly good skills should be easy.
Winisd, bassbox pro, and sonosub builder(sorry no links this time brother) are great resources to use, and simulate with unit you go to put blade to wood.
Not sure anything useful here, but even a little bit can go a long way. Have fun!
