How can I improve this listening environment? This photograph was taken from my listening position.

Soon I will be adding a pair of B&W 800D speakers with matching Classe M400 monoblock amps. I want to be sure the room allows the rest of the system to function at it's best.

The rooms dimensions are roughly 23 x 22 x 8-feet. But there are 4 wide openings to other spaces which makes it a bit hard to say what the dimensions really are.

There are a lot of hard surfaces; large windows on the back wall (facing south) and hardwood floors.

I'm considering adding drapes. Any other ideas on how to improve the room and keep my wife happy?