Having an easy acces to all Scan Speak drivers, I was tempted to try the new super models: the 15 W and neodymium revelator 9600.
I studied many different possibilities, and decided to go for the full WMTMW.
I put the 10 inch 8565 in a sealed box sized for Q=0,6. To improve transient response and increase bass I added a 8 inch 8555 at the top, in smaller enclosure, still maintaining the Q=0,6. This all  translates into 110 liters for the former, and 37 liters for the latter. The top box is suspended by the side wings, to eliminate bass vibrations from messing mids and highs. In-box resonance  is 26 Hz and 33 Hz respectively.
The mids are symmetrically positioned around the tweeter, which is so small, it allows for very close spacing of midranges.
To eliminate wall vibrations I used my own idea of midrange enclosure. I built a relatively light plywood box (1 cm = 1/4 inch) and the midrange cavities are mineral water bottles. A plastic bottle, 5 liters each, is glued to the front baffle. The space around bottles, between the bottle and the box is filled with sand. So the vibrations of the bottle body should not propagate outside of the box. Bottle interior is filled 100 % - half rockwool and half wool.
The XO is located in a sealed space behind bottles. Each driver has separate bottle.
The boxes are heavy and very dead sounding. The black boxes are veneered with maple root, and the midrange box and side "wings" are a mixture of solid mahogany and mahogany veneer over birch plywood.
The listening proved, that there is no sound emanating from enclosure sides. This is a painful thing to build, but sounds very clean indeed.
 

The crossovers are made with North Creek components - ZEN caps and GOERTZ coils. Ohmite resistors and silver solid wire.

The good thing about this whole setup is that I can move the mid/high boxes without moving the whole construction to get perfect imaging. Everything weights 130 kilo per side (280 pounds).

Overall, there are very fine speakers. Maybe the cleanest sounding speakers I ever heard to that date. The bass is awesome and very musical. Mids are sterile and suspended in the air like I never heard before.
The top end is very nice, maybe 5 % worse than the big revelators. It blends with the mids nicely and seamlessly.
LC Audio xo does wonders here - sound, especially vocals are hyper natural.
The impedance is as flat as it gets. It stays within 3,9 and 4,7 ohm limits !!! An easy 4 ohm load for my tubes.