Diffusion or Absorption behind the speakers?

Agree with Tiger. I found diffusion on the front wall between my speakers gave me a very ‘alive’ and vibrant sound, yet still detailed, accurate and natural. It also seemed to increase my soundstage. Both corners behind the speakers I have DIY bass traps (R19 rolls)

Absorption on front wall between the speakers tended to make things a little dull.

Regards
Paul

I've experimented with both diffusion and absorption to no end. Absorption for bass, tube traps in corners an absolute necessity. As far as the mids and highs, I've been all over the place, absorption alone, diffusion alone, and a combination of both. Currently I'm using only absorption (only on middle of front wall), as it seems best with current state of system.

I've found that using diffusion/aborption or a combination of the two mostly affects soundstaging in my system and room. Diffusion brings soundstage forward, absorption rearward, I change treatments in concert with changes in my system.

I would also second Shadorne thoughts diffusion seems to work best in a very large room . Bass trap's are what most people need in normal size rooms only after you address this should you think about diffusion. I would also address the first reflection point with some absorption before adding diffusion unless the room is very large. I only use absorption in My 23 foot by 17 foot room a nice size room and My speakers have a rear tweeter . I have the speakers about 5 feet out from the wall and have a trap on the wall between the speakers along with every corner and first reflection points plus a couple of others. Marc