Who makes a hi-eff 15 that can do a 50 hz F3 in a sealed 3 to 5 cu ft?

Hi i ended up with a nice proac super tablet from my uncles bedroom
ok the reason for a f3 at 50hz and a 3 to 5 cut box is that i have an old 3cuft sub box and a 5 cuft box
i have a pair of altec santana with the biflex woofer for my home theater and had upgraded the twitter to a pe planner ribbon tweeter and wanted a similar driver with the smaller box and there are many tweeters with waveguides or some ribbons that work well without drastic attenuation ,for the bigger box i have a few horns that play well in the 95 db range(hepner,magnavox,sansei etc) ,i also have many other cd drivers and horns that i wanted to experiment with.
there are plenty of subwoofers for me to play with(BR,ppsl,th,etc)
so the ask was a woofer that can do this,
freed i like that idea but what does it do to the phase and inductance?
and thanks for the links to the other potential drivers and will look str them over the next few days
is there a driver like the alter 420A ?
thanks in advance and your patience