Hi Kevin. From my experience, Thiels are a bit tricky when it comes to getting a wide soundstage out of them. I was never as happy with them in that regard as I am with my current setup (I owned the 2.3's and the 6's). So, it might not hurt to audition other speakers. However ...
Having one of the speakers next to a large opening will not help matters. Can you move them back by a couple of feet to allow for some direct reflections from a side wall? That could help.
Also, I'm not sure about your speaker wires. Thiels are pretty sensitive to the right wires in my experience. It wouldn't hurt to try some different ones. I would recommend home trials so you don't commit to buy until you try. My first suggestion would be MIT cables. But, read some past threads for other fine recommendations.
Finally, I would also suggest trying speaker cones under the Thiels. Big, big difference. You will hear it immediately. There are lots of places to get these, but Thiel usually supplies some with their speakers. This would be an inexpensive and highly effective tweak that should help with the soundstage.
Good luck.
Having one of the speakers next to a large opening will not help matters. Can you move them back by a couple of feet to allow for some direct reflections from a side wall? That could help.
Also, I'm not sure about your speaker wires. Thiels are pretty sensitive to the right wires in my experience. It wouldn't hurt to try some different ones. I would recommend home trials so you don't commit to buy until you try. My first suggestion would be MIT cables. But, read some past threads for other fine recommendations.
Finally, I would also suggest trying speaker cones under the Thiels. Big, big difference. You will hear it immediately. There are lots of places to get these, but Thiel usually supplies some with their speakers. This would be an inexpensive and highly effective tweak that should help with the soundstage.
Good luck.