I run my Outlaws in extended mode to get down to 15Hz... I'm probably 90-95% music. Zero concern should be given to the ported/sealed argument... rather all concern should go to low distortion output.
Just using them as an example, the outlaws are 13.5” cones, and bassaholic rated here for extreme room size. That’s 5000’3. I’ve got two in my 2000’3 listening room.
Perhaps overkill, but I don’t have to run them hard, which means I have gobs of overhead and very little distortion being produced.
Once you get a reasonable estimation of your room volume, you can start to really narrow down what you need to pressurize your room. But 15” Hsu options should have no problem with your room. Pb 3000 would be good, but 4000 series, Pb or Pc would do you better.