I realise that what I wrote in post 11 could be read as a little ambiguous. I want to make it clear that the arrangement of the equipment you have made is correct: having the speakers on the long wall and firing across to your listening position on the other side. This is exactly the arrangement as recommended by Peter J Comeau.

The only possible improvement might be to move the system a little to the left, away from the window. And of course, put up some heavy curtains for the window.