I now have the pair pictured in post #15. I have not measured them in any way yet. I stacked together a slightly larger bedroom system and just dropped the GTI1000's in a pair of .7ft3 sealed boxes with one pound of fiberglass until I get around to building some that fit in the bookcase and they sound surprisingly good just like that.
I have never seen a pro or consumer counterpart of this speaker, that surely doesn't mean there isn't though.
I'm not using them above 100 Hz but if there was something I could measure that would help you out let me know.