Absorb or Diffuse in between speakers?

I also have a fireplace (fake) with a glass front between my speakers (Silverline Preludes). The speakers are about 8 inches further into the room than the (still fake) fireplace, and 7 or so inches from the edge of the aforementioned (fake) fireplace, so reflections are gonna go sideways and it doesn't seem to hurt soundstaging, imaging, musical content, phase, or lyrical sensibilities (maybe that one a little). I've pulled them into the middle of the room and otherwise tried various degrees of tow-in, height adjustment, spikes, etc., and they sound best pointed straight forward raised up on butcher blocks with vibrapods under them. Also, the little corner the fireplace creates behind the speakers is perfect for a little REL Q150e sub. This information is useful only to me or those exactly like me with identical gear in a room exactly like mine.

lol! +1 Wolf

Wolf, I doubt that there is anyone else exactly like you. Meant in a nice way, of course.

>>Absorb or Diffuse in between speakers?

I would say that it depends on the speakers and on your room. As a rule of thumb, I usually absorb between box speakers and diffuse between dipoles and bipoles. But again, it depends on your room.

Rather than blind testing, I would suggest that you spend a little time and a very little money and perform an analysis on your room. I know that this seems like less fun than just blindly buying a bunch of treatments, but it will almost certainly result in better sound.

Both GIK Acoustics and RealTraps have posted a lot of free advise on their web pages. Start here: RealTraps - Room Measurement Series

and here: RealTraps - Acoustic Articles

It's really not at all hard to do, once you understand the basics, and will definitely result in the best result.

"As a rule of thumb, I usually absorb between box speakers and diffuse between dipoles and bipoles"

Omnis diffuse naturally and save having to deal with directional issues for the most part.