A general observation.
Many so-called bookshelf speakers really are intended for placement well
away from room boundaries. This is an interesting and useful condition that
can lead to remarkable sound, but it doesn't apply to your situation.

The bookshelves in which I use my Atoms are open-backed and three feet away
from the wall. They're also on the top shelf. I wonder if this would be why I
like them on shelves as well as I do?