I have a similar situation, my room is 15'x 13' with catheral ceiling and opening on the right side. I have my equipment setup similarly. The only difference I think is I have about a foot(12in)of wall on the right side before the opening occurs. I'm using floorstanders with excellent results. Is there any portion of wall on the right side?
If not, I'm not sure if floorstanders would help or not. Probably would be a little better but still not ideal.
If not, I'm not sure if floorstanders would help or not. Probably would be a little better but still not ideal.