Well, no reason why Mini owners can't just use servo subs instead of the powered woofers. Just disconnect them and/or don't turn them on and use the servos. Preferably open baffle servos to match the speed and sound of the Mini's.
That would make for a very interesting project for Danny or someone else. Redo the Mini's w/ the main 3 drivers and replace the powered woofer w/ an open baffle servo sub, one for each side. Might also be interesting to replace the midbass coupler w/ an open baffle driver as well. Then you'd have the first hybrid planar/open baffle speaker (at least that I'm aware of). No idea how well it would work, but can't see any reason why it wouldn't sound terrific. Sheesh, the more I think about it, the more I'm 
Sign me up!
Does a pair of minis with a pair of the prebuilt sealed GR servo subs count?
I played with that setup for a while. . . very nice, no doubt! Which brings me to my problem with the setup. I really wanted to use the powered woofers in the mini to get the stereo "woofer" frequencies in, you know, stereo; from there on down, "subwoofer" frequencies (meaning below 40hz by my definition in this exercise) would be managed by the servos. My problem was the servo bass. . . no matter how much I tweaked on it, the servo bass was just that much BETTER than anything the minis' powered drivers could deliver that I just couldn't find a good blend from the mini driver down to the servos. . . so I just crossed the minis at 80Hz, unplugged the amps, and let the servos do their thing. Now don't get me wrong - the woofers in the minis do very well, and if I hadn't had the servos right next to them to A/B, I probably wouldn't know I was missing out on anything. It is just that the servos really are on a whole higher level.
IMnsHO, the mini reborn as a fully sealed design with front firing servo sub drivers in each cabinet (heck, if you're really feeling crazy a pair of the 8 ohm drivers run off of one amp per "mini") would both eliminate some of the placement challenges with the mini as-is, and take the whole thing up another notch - picture minis doing all of the music that they do so well now. . . and throw in some pipe organ!
On another tangent, I got to thinking about the whole dual 8 ohm servo drivers per amp thing. I was thinking that with a good 100Hz-up design and a little creative planning one could build a very powerful, effortless, HT and big scale music kind of speaker; sort of a "poor man's" Catalyst is what I kind of had in my head. . . For a second, I just imagined having six servo subs across the front of my room doing mid-bass pans during action movies.
Sean, on yet another track, just out of curiosity I read a post of yours above discussing the cabinet size and front baffle dimensioning on some of the imagined mini designs. Unless I misread, you suggested that the front baffle size would change or affect the crossover. How does that work/in what way? Not being provocative here, honestly trying to learn a bit about the black art of crossover design - something I don't know too much about.
