Thank you for the very prompt and thorough response.
I like the frequency response for some reason I generally prefer a speaker in which efficiency begins to tilt downward a little above the mids/lower treble.
Regarding efficiency, power, and loudness I will play it safe and ensure I have enough headroom, so perhaps 4 - 6W with the 4 Pi. Thanks for also confirming their SET-friendliness.
I am not sure what my options will be wrt sub placement. I would like to use distributed subs but cables across the floor could be problematic. I will probably enjoy the Pis on their own or with a front wall positioning of subs, but will see what I can do re: sub distribution.
Thanks for the info regarding driver to driver positioning kinda what I thought. The speaker design should be workable as a two-box (er, four box) solution. I'd love a pair of Pis with the wood horns sitting on top those little babies are a work of beauty.
What I am planning then, is a pair of 4 Pis - with JBL 2226 and B&C DE250 - in two boxes, with the H290 centred over the 2226 and maintaining the fore-aft alignment. Place the port on the bottom of the cabinet. Hopefully this will not be too unrealistically difficult when it comes to the details...
Questions:
Does removing the H290 from the box significantly affect box volume/2226 loading - should I decrease the box size or amend the port dimensions slightly to compensate?
If and when I decide to use the wood horns, will it be relatively easy to set the vertical and fore-aft position of the horn?