Would diffusion help in this space

Wow, you've been playing with this for a while!

I haven't read all of the posts involving potential solutions so forgive me if I miss the mark by a mile. If your latest photos reflect your present speaker set up, and I have read your comments correctly, your speakers are seven feet apart and your listening chair is only 4 ft back. I would think that first reflection points on the side walls are not an issue and neither diffusion nor deadening wall treatments would help you much, if at all.

You didn't ask, but when I look at your photos, what stikes me initially as being a potential problem which will screw up imaging is listening to the speakers from 4ft away. Something closer to an equallateral triangle would be much better. Move your chair back to 7 ft or move the speakers closer together. Personally I'd try to get the listening position further back if you can. Perhaps a combo of both. In theory at least, you would get a better centerfill and solidify pin point imaging (which is what is necessary for great depth of image). In theory!

Good luck.

FWIW.

What's behind your chair? Diffusion works best on the back wall behind your chair. I see you have some GIK 244 panels. How did you arrive at those positions? Did you experiment with a lot of different positions or just pick the spots that seemed right?

I've been using a combination of 242,244, monster panels, and Acoustical Solution diffusers. I've done a lot of moving panels around the last six months to reach a balance that I feel is right. I think you need to try many different panel placement options.

From your photos, I would start with one of the 244 panels centered on the frt wall behind the speakers, move the other 244 panel to the back wall. It also looks like you have a 244 panel on the ceiling between the speakers. I tried a 242 panel hung like a cloud and it lasted only a week before I removed it due to a reduction in acoustic space. Maybe remove the ceiling panel and try a thinner panel there or a diffusor.

Thanks for the replies

A few corrections

I have my speakers approx 6 10" feet apart in an equalateral triangle
My listening chair is 4 feet from the back wall

Sorry if that wasn't clear in my systems page
I don't have any ceiling treatments

Is that just a drop down in the ceiling that I see in the photo of your speakers from head-on?

Yes it is
To answer your other question
I experimented quite a bit with different placements
GIK acoustics also worked with me on the room and placement options