OK, here's the short answer. The biggest obstacle to optimizing my room acoustics is: the room, my den, is just too small!. How I plan to overcome it: Simple! Build a bigger room in the basement. Wifely approval has already been granted. Not only that, but the suggestion of making it into a full blown HT did not elicit the fatal raised eybrow! Woohoo!
Now, the second biggest obstacle is that I can't afford to hire Rives to design it from the ground up. But the Rives Test CD will help me to fine tune my room design. I might however spring for some room measuring software like ETF.
I've been reading on acoustics for a year now and have some ideas for the room such as: Architectural details such as pilasters on the walls and a coffered ceiling for diffusion. Resilient channel mounting of drywall for both soundproofing and (more important) increased bass absorption by the walls -in effect making the walls bass traps.
My dipole speakers benefit from a fairly live and diffuse environment according to their designer, Siegfried Linkwitz. Testing in our living room (within the limits of spousal tolerance) confirmed this. I may build some quadratic residue diffusers and deploy them to scatter first reflections. Hopefully, those will be the only overt "acoustic treatment". And I think I have some nice ways to disguise them. Any mid to high frequency absorption will, I hope, be accomplished via carpeting and furniture.
And then, any Audioholics who live in or visit the Detroit area will be welcome to be staggered by my DIY genius! Pizza and beverages on me. Yes, you may consider that a bribe.