There are different ways to skin a cat. You certainty need a low FS. There are two approaches you can take. You can use a low QTS with a lot of Xmax and use EQ to compensate for the quick roll off. Or you can use a driver with a High QTS (.7+) to get a response well down near the FS of the driver.
The latter generally limits your selection to drivers with a small xmax. My advice is if you are set on going IB with 12 inch drivers, do the install and try it. If you got a lot of excursion to work with (and obviously a lot of cone area), you should get plenty of output. If they don't work for that particular alignment, sell them and try something else
The latter generally limits your selection to drivers with a small xmax. My advice is if you are set on going IB with 12 inch drivers, do the install and try it. If you got a lot of excursion to work with (and obviously a lot of cone area), you should get plenty of output. If they don't work for that particular alignment, sell them and try something else