"I've also been lead to believe that while a pr
unloads just below tune like ported, it regains control of the woofer further down in frequency unlike ported."
below tuning in a p.r. design, the cone that is receiving the power blows out of control just like in a ported design.
below tuning in a p.r. design, the p.r. does not blow out of control below tuning because there is no longer anything coupled to it, so p.r. excursion maxes out around tuning frequency, then stays at that level below tuning.
"There is always going to be the mechanical resistance of the suspension on the PR
. That should help to maintain resistance on the woofer below the tuning frequency."
that's not quite how it works. below tuning, the powered driver is no longer fighting against the p.r. frequency response falls like a rock and cone excursion explodes.
"One of the finest subs I've ever owned: The Definitive Technology Trinity, utilized (4) PR
's and had some prodigious output, in-room. And perhaps the point raised above about it being better-behaved down low over a typical ported design had something to do with why I NEVER heard a bad sound out of it, even when seemingly pushed to its limits in my room (120+dbs)."
many well designed commercials subs have custom designed limiters so that you don't every find out for yourself where the sub starts to sound bad.