First try aiming the speaker with the "open background" more directly towards the listening position (than the other speaker).
If this sounds better then experiment with the various/slight angles.
Then try the 13' spacing.
DeKay
Question on Speaker Placement
Based on the shape and content of my listening room, I have one speaker with a back wall directly behind it ( roughly 2') while the other speaker is backed by the open entrance into another room. What are the sonic implications of this arrangement? I'm limited in my ability to test alternative positions, although by widening the distance between the speaker by about 2', I can back the 2nd speaker with a wall. This would be about a 13 ' distance between the speakers. The speakers are PSB Imagine X2T. Hope this makes sense and thanks.