Absorption, Diffusion or a combination of it all?

All…thanks for your thoughts! 
I watched the video and it makes sense but isn’t easy to implement, no room is ideal as far as wall space, ceiling, windows, doors, etc. Good as a guideline though.

So since I’m already using the GIK 242 and 244 bass traps in the corners, I’m thinking to add a set of A2 Alpha Pro, exactly the same design pattern @thyname has in his room. Decent amount of absorption and enough diffusion. I don’t want to completely deaden the room. Still researching. Keep the thoughts and suggestions coming. 

OP

If you look at my virtual system you can see how I implemented the video. Interleaf diffusors and absorbers, pretty simple. 2D diffusors in front half of the room and 3D diffusors in back. Absorption on the back wall directly behind MLP with diffusors to each side. 

I initially started with 2 GIK quadratic diffusers on a shelf in front of my tv screen between my speakers. I liked the results so much that I purchased two more and put them atop the original pair.

I’d definitely recommend either quadratic diffusers or something like GIK Alpha panels. The latter have the advantage of providing both scattering and some bass trapping, if you get thicker ones.

For what it’s worth, Paul McGowan prefers diffusers to absorbers; the former mix reflections of all frequencies equally, while the latter absorb different frequencies to different degrees. McGowan also explains that the reason “first reflections” cause problems for imaging and soundstage is that they arrive at the ear “too quick for the brain to sort them out as delayed copies,” so they muddle the spatial effects of the perception of the direct sound.

It's easy to make a diffuser. Go to Home Depot and buy a long, square wood pole. Using a skill saw, cut it into lots of small cubes with angled cuts. The angles don't need to be precise or the same, nor do the cubes need to be the same height. In fact, the diffusion pattern is actually enhanced by irregularly sized and shaped pieces. Softer woods absorb more than harder woods, but either will work. Then glue them, flat side down, onto a board of the size you need. If you want to absorb some lower frequencies, glue them onto an acoustic ceiling panel (also available at places like Home Depot). Works well and looks good, too.