Peter,
I actually was actually doing my final measurements when the (M2 sized) bookshelves were on my stands on inc from the ceiling. This afternoon I was actually thinking I might go with direct firing for the backs since the Qs kept being set to 150Hz x-over by Audyssey/1909. I just went and checked the bracket on the Q's. If I put the 1/4" mtg hole 1" from the end (2" would have been a little better), the 27º tilt has the top of the 5 1/4" surround rubber 4 1/2" from ceiling, while the lower part of the surround would be 6 1/2". I don't know if I would have wanted them lower anyway. Good thought though. You did catch me designing to another speaker. ;o)
