There are several threads dealing with Atmos. If you search on "atmos" in the forums you'll find them - though I'm not sure if there's any new developments from Hsu in that regard.
And as to your other inquiry, a similar question was asked earlier this year and got a reply. Not sure if it's EXACTLY what you're looking for though...
Originally Posted by Kevin_Hsu
Honestly, our 15" subs can get you pretty close to that. Technically you can EQ any sub to go as low as you want, but whether you actually get significant clean headroom at those frequencies is another thing. Really when it comes to subwoofers, it's all a balancing act in the driver design (excursion, mass, efficiency), amp power, enclosure, port design. If we were to design one, my guess is that we would have to put it in a larger enclosure and go with a larger driver design, as you stated. That's not off the table for sure and we're always coming up with new ideas.