Spacing Diffusor Panels

I agree, you don’t want diffusion too close to your seating position  or speakers because comb filtering can become an issue.  From what little I understand that effect is partially dependent upon the effective frequency range of the diffusion panels which is determined by their well depth.  The diffuser I’m using is a simple one-dimensional DIY design (they’re called HomeDepot Diffusors 
https://www.google.com/search?rlz=1C9BKJA_enUS796US796&hl=en-US&ei=5atMW-

They are hanging on the front wall approximately 6.5 - 7 feet from my Magnepan’s.  Actually they are sitting directly on the floor at this point, I haven’t gotten around to mounting them on the wall yet.  

It’s my understanding that the sound coming out of the Maggie panels, front and back is exactly the same; only they are in opposite phase.

i’ve tried Absorption and did not like the result; just deadens everything especially the top end.

The diffusors do expand the sound field behind the panels and I like that effect.  Balance is the key; not too much diffusion and not too little.

that brings up an interesting question; what 'sound' actually comes out of the back side of Magnepan's?  Is it an Exact duplicate of the sound waves that are emitted from the front?

If the sound from the back of the Maggies is 'not good' then why would you want it reflecting off of the front wall back into the sound field?

But, more listening is required.  My initial impressions are that in general the sound is better overall and that the room just seems more natural sounding with the diffusors on the front wall.