Wayne,Thanks for all the considered suggestions! One issue is that I have already done MAJOR mods to the Heresys... upgraded the crossover caps, rewired most of the crossover and the drivers, replaced the backs, added binding posts, fully damped the horns and woofer basket, lined the interiors with fiberglass and loosely stuffed them, and braced them with 2" dowels.
It's interesting, but I wonder whether I should just go with a new speaker instead! I've put SO much work into the Heresys, and as much as I like them, I think the real problem is that they don't mate with my room very well.
What do you think of me using Pi cornerhorns with rear baffles?
Thanks again Wayne -- you give advice way beyond the demand of duty!
All the best,
J!