David,
Yes, all of these measurements are near a corner.....in fact, they are all withing three feet of each other. I have two more locations to try, but it requires rearranging some furniture. For reference, my room is 14x18, with a sloping ceiling that goes from 8' to 9'.
Interesting, I was messing around with the BFD lastnight to learn about it, and came up with this:
I also learned that taking measurements at different listening levels has a somewhat dramatic effect on FR.
Probably won't have much time to do much measuring today.