what should I get to replace what I am planning to try

So I have speakers that are too close to the wall. The image is now actually behind the wall, which is in the kitchen. But I can't sit in the kitchen too long my wife is mad. 

I was thinking that it must be my tube amp, right? If I had better speaker cables, I could spend all that leftover money on a sub. Btw my budget is unknown and so my room dimensions. (it's a triangle shape though). 

Please help!