I think that’s a great example of how sound absorbers can destroy musicality. From the experiments I’ve done, it sounds best with the absolute minimum of absorption needed to just tame the flutter echoes, and certainly not at the first reflection points! - the reflection needs to be as near to the direct sound (spectraly) as possible, so we can encourage some lovely coherent envelopment in the room (as long as the delay between the direct and reflected sound is less than 25ms). I think the problem is that anything that absorbs sound does so non linearly, this messing up the rooms linearity, which is obviously not a good thing. I purposely chose leather furniture because the absorption characteristics are more linear than upholstered furniture. Feel free to call me a sad b’stard for letting the hifi control my life!
These modern diffusers are often touted as the answer, but from what I can see they’re even more non linear than sound absorbers. I’d like to try the old fashioned curved reflector/diffusers, but I haven’t got round to it yet. Also, what’s holding me back is they’re all so fekin fugly!