My new studio in Sketchup. Needs suggestions. Please help

True, true.. thanks for spotting it. Thats what I love about forums. I have worked so long with different designs that I have lost the focus. Definatly fixing that.

Would it be enough to do something like this? Making some kind of rounded diffusers?

The speaker angles in your drawing are correct - except your door is in the way of where the speakers should be.

Yes. I was thinking of having them over the door facing downward. Probably not 100 percent correct, but I seldom do 5.1 surround miksing and will probably have them down in front of the door when I do it. I will not have them buildt into the wall. They will be on stands. I know this maybe seem crazy, but I have to do some modifications since this is the best solution of the rooms (so far) and my budget is not up there with the really expensive studios. The room that where probably be building in is not perfectly a square. That is why I found it difficult to match you perfect studio plan, witch was the starting point basis for my controlroom. I would loose to much square meters that way. Will it work with the rounded diffusers?