Room Treatment for Corners - Recommendations?

The 8 foot ficus tree idea came from Dr. West the man who designed my Soundlab speaker. This particular tweek is a universally accepted way to diffuse the sound coming from the back of my speaker.

He actually sells a tall device that diffuses, but they cost over $1500 and this is a great alternative. Many Soundlab owners have found diffusing the sound behind the speaker (not absorbing) to be quite helpful. The sound is not merely different, but is more natural and focused from the listening possition.

I love my Rives designed corners. They really disappear and look quite lovely.

Of course they are a lot more expensive than GIK tri traps.

As a matter of fact, I did AB artificial and real plants, and real won every time. I suppose if the fakes are heavy and absorptive, they can work... In my experiments, artificials did nothing. Draperies...even thin and light ones work very well. My room was transformed with the addition of light, drapes over the windows. I really didn't want them - I live in the desert of Arizona, and the views are beautiful, but careful selection of drapes work fine.......trial and error

Specifically for ceiling corners, I use and can recommend Cathedral Sound panels . You can buy them at Cable Co. Sometimes they come up used here, though rarely.

Outlier - nice name! You into statistical analysis by chance? I digress . . .

You mention ceiling corners and there's lots of fiberglass-type absorption products you can use, just be sure to leave a healthy (6"+) air space between the wall surface and rear of the absorber so that it works across a broad freq spectrum and doesn't act as a low pass filter which would throw off the timbral balance of the reflections and reflections of those reflections.

Have you considered a hemi-cylindrical diffuser (often called polyfusers or polys for short) for the floor-to-ceiling corner? They're made from Sonotubes used at construction sites for concrete pouring. If you use a 180degree arc then it'll diffuse in about 120 degree pattern and you can stuff the interior with OC701 or 703 fiberglass to act as a bass trap. The curved surface facing into the room should be hard enough to prevent absorption of mid and high frequencies. Use a radius with a minimum of 12" (24" diameter) and finish it off with some kind of Guilford or Maine cloth or what I did with stained wooden veneer:

http://i1126.photobucket.com/albums/l620/kevinzoe/Frontwallhemi-1.jpg

Match the wooden veneer to your speaker's or fireplace bricks or wall colour etc etc. Just a thought and hope it works for you.