You have a major issue with a room that size. It is tough to do anything excet listen in the nearfield, which it soulds like you are already doing. Can you get your speakers out a bit more from the back wall and move your listening chair back, maintaining the triangle ratios?
Bare walls is a major problem as well. Time to get up some diffusive and or absorbent materiels, especially on the side walls.
Lastly, try toeing in your speakers until the axis cross in front of your listening position. This will take of some of the 1st reflection problems from the side walls.
BTW, I wouldn't worry so much about the wall behind your speakers - that is a relatively minor problem compared to the others.
And, needless to say (but I will anyway) you will overdrive this room a very moderate volumes so don't expect to ever listen to loud music and enjoy it.
Hope that helps a bit.
Bare walls is a major problem as well. Time to get up some diffusive and or absorbent materiels, especially on the side walls.
Lastly, try toeing in your speakers until the axis cross in front of your listening position. This will take of some of the 1st reflection problems from the side walls.
BTW, I wouldn't worry so much about the wall behind your speakers - that is a relatively minor problem compared to the others.
And, needless to say (but I will anyway) you will overdrive this room a very moderate volumes so don't expect to ever listen to loud music and enjoy it.
Hope that helps a bit.