Here's "Stonehenge's" front wall with the new 2'x4' Monster in place.

https://www.audioaficionado.org/pict...pictureid=4661

I've done only one audition since installing it and listening with the flipped-to-horizontal 1'x4' Monster above it at the wall-ceiling intersection...to Leonard Bernstein conducting the New York Philharmonic in the fourth and fifth movements of Bela Bartok's Concerto for Orchestra (rip of a Sony "Royal Edition" SBM'd CD). But it's already obvious that treating the wall-ceiling intersection makes a noticeable improvement in the perception of bass definition, ensemble coherence, the sense of instruments "working the room" they're performing in, and the rendering of intra-soundstage space. One other benefit: The listening "sweet spot" has broadened considerably.

This completes "Stonehenge's" physical configuration.

The only downside: Mrs. took one look and informed me that (1) I'm getting rutabagas for dinner and (2) I'm on probation for an indeterminate period. Oh, the sacrifices we make in the pursuit of audio excellence.

A slight tweak or two...
 

I've wanted for some time to see whether correcting the asymmetry in front-wall 244 placement would have an appreciable effect on what I hear in the bedroom system. So I finally took a break from knocking out a for-the-fun-of-it Cold War spy novel and moved the left 244 from the corner to a position behind the left speaker that corresponds to panel placement behind the right speaker.

The result is a more coherent, better-balanced soundstage. But denuding the corner of treatment resulted in a slightly less resolved overall presentation. So my second step was to remove the horizontal 12"x48" Monster from atop the center Monster and mount it vertically in the now-empty corner.

Space limitations forced me to initially mount it "sideways"--i.e., with the panel facing straight at the opposite side wall--until I come up with a way to angle-orient it toward my nearfield listening position. Nonetheless, even with that compromise, the sonic presentation has "tightened up" and at the same time "opened out", resulting in a net improvement over the original configuration.

Here's how it looks:

https://www.audioaficionado.org/pict...pictureid=4849

https://www.audioaficionado.org/pict...pictureid=4851

And finally...
 

Restoring the 12"x48" "top" of the center Monster "T" to address wall-ceiling intersection effects at that location increases both the apparent spaciousness of the soundstage and improves overall resolution and ensemble layering.

https://www.audioaficionado.org/pict...pictureid=4852

Done.

I should know better than to post "Done"...
 

I've just placed orders for some GIK Alpha 4A 1D panels to allow me to listen-test how reconfiguring the room's diffusion/absorption profile would affect the listening experience.

Preliminary information indicates that the 4As will ship the first week of February. So I expect that some time after that I'll post my listening impressions...in a new thread here.

'Til then...

That is starting to look a lot more like a lab than a bedroom Jim. :D Let us know what your results are, acoustic treatments when deployed properly sure do go a long way to improving the sound magnitudes better than component upgrades.

She won't say it out loud, but the now-and-then side-eyes I detect directed at the room walls indicate that my wife concurs 100% with your characterization, Serge. :D

And I agree on the magnitude of performance bump afforded by appropriate room treatment.

I guess that balances it all out.

New Alpha 4A panels installed
 

Photos and diagram are in the GIK Picture Thread, Post #17:

https://www.audioaficionado.org/show...t=44207&page=2

I'll post listening impressions after I've had more time to listen to the new configuration. (And, yes, Serge AKA PHC1, it does look more like a lab now.)