Wow, this is the first time I've ever seen something like this. What are those things along the wall?
I know Michal, they are weird looking things. Some times people come in the room and stare at them. They either shake their head, roll their eyes, point and laugh or say maybe they can work.
They are a DIY diffuser that, an EE friend made for his living room. He brought over a pair for me to try. He didn't tell me he was bringing them as I might have said "Yea, I don't think so".
In reality they are plastic disposable martini glasses. The bottoms discarded and they are glued to pieces of 1/4" foam core board and painted.
I realize they aren't for everyone and possibly no one but they made a change in the sound I would have never guessed.
When I built my listening room I wanted to start with total absorption then go from there. Many visitors shook their heads with the silence in the room but I didn't mind.
When we started placing and moving the first two 50 Shades of Gray* panels around it was very obvious how you could change the sound.
*50 Shades is a movie reference comment by one of my wife lady friends made upon seeing them the first time.
Anyway, I have slowly added more as time goes by. I think I am about there but, not totally sure.
There is clearly not much of a WAF there to put them in your living room though.