You and I sit in similar positions. I'm about 8.5 feet from the speakers, and the speakers are about 8 feet apart.
In my experience, moving the speakers closer together also resulted in a deeper image, but more contained between the speakers. Having them wider apart created a wider image that extends out beyond the speakers. Finding just the right distance is tricky!
Moving them closer also had the effect of moving the first reflection points a bit farther down the side walls, so this likely helped as well. Toe-in will also affect the location of the first reflection points. You know how to use a mirror (and a friend) to find the first reflection points, yes?
In my experience, moving the speakers closer together also resulted in a deeper image, but more contained between the speakers. Having them wider apart created a wider image that extends out beyond the speakers. Finding just the right distance is tricky!
Moving them closer also had the effect of moving the first reflection points a bit farther down the side walls, so this likely helped as well. Toe-in will also affect the location of the first reflection points. You know how to use a mirror (and a friend) to find the first reflection points, yes?

