difussor's

While checking back here, I noticed an error in my post above -- my DIY diffusor is a 1D diffusor,  Which is probably the kind you want, 2D diffusors tend to diffuse too much energy toward to floor and ceiling, so that much of it dissipates before it reflects around off multiple surfaces to reach your ears; not a lot different effect than just using an absorber, IMO.

I'm curious as to why one would wish to place diffusors on the front wall with forward firing speakers?  The rear wall and or ceiling would be the correct location.  I would tend to think live end front wall and dead end back wall would be the place to start.   

thats true rhl...work in progress and that does make more sense...but the back wall is a folding closet...sooo

With the Adagio's 30" out, and the small size of the room, isn't this a near-field setup?
Diffusion panels on back wall, and ceiling is a good idea.
Absorbtion panel only on wall behind speakers to focus the image.

If the the wall behind your listening position (back wall) is a folding closet, you can try using some fabric wall-hangings. Or something similar to stop standing wave reflections.