Planar Speakers and Diffusors

Try the diffusers, and let us know what you hear.  Generally speaking, I've read here and elsewhere that absorption is better on the front wall (behind the planars).  I have tried everything from nothing at all, to slight absorption, to full absorption (but never diffusion), on the front wall. 

The absorption does change the character of the sound, but I would describe it as more precise, more detailed, with better imaging.  Without absorption, there is quite a bit of sound that bounces off the front wall, and distorts the precise soundstage.  But it does sound "brighter" without absorption, so if your system sounds dull, then perhaps, no absorption will be better, although perhaps the musical imaging will be slightly more blurred.  

Experiment with your ears, and find out what's best for your system and your room.

@ozzy 

Thanks for sharing your experience.  Next, you may want to try adding absorption panels behind the speakers.  Start with a few, and see what you think:  perhaps you will find the imaging more precise, and the sound less bright.  Whether that's a desirable characteristic for your system will have to be determined by yourself.  There are many places that sell sound absorption panels.  

I started off just placing absorption panels directly behind both speakers, and I appreciated the sonic improvement, so I placed absorption panels on the entire back wall (with bass traps in the corners).  It does make the sound quality less bright, but more detailed.  It might dull the sound too much for some systems.  

@kykat 

Yes, thanks for catching that!

In that last post, I typed: "I placed absorption panels on the entire back wall (with bass traps in the corners)."

I should have typed "on the entire front wall" (behind the speakers).