OP
Diffusers behind the speakers on the front wall. Absorbers on the front wall will close the stage, speakers will not disappear as the stage will be behind the speakers; don’t believe, try it. Diffusers on the front wall will disperse the reflections and you will hear an improvement in both depth and width, and speakers disappear, at least that’s my experience. Putting a few random panels up on the front wall or only behind the speakers will not help much; best is as a large panel between the front speakers.
Multi diffusers/absorbers best on the side wall at the first reflection. You don’t want to kill the room but you do want to control it so the sound from your speakers will hit your ears before the first reflection of the sidewalls. I do nothing on the back wall as you want reflections from the room. Speakers need a room for many reasons… it’s about controlling the reflections. Simple test, is take your system outside and hear how horrible it will sound.
Can’t just do one or the other. Vicoustic is another manufacturer that make both products, which is what I use. Every room is different, and everyone has their opinion what’s right, so buy both types of panels and return what doesn’t work for you.
I suggest watching the hour long video because a lot to learn, and maybe watch others as you’ll probably discover they all support it each as it’s science/physics and can be tested and proven. Lastly pull your speakers into the room and same with your listening seat off the back or unlikely any treatment will help much.
Have fun and good luck.
