Hi Murph,
The auto-setup modes of most AV receivers tend to be notoriously inaccurate and error-prone for subwoofers, and, as you found, sometimes indicate the sub is 28 feet away when it's close by. There are so many variables with standing waves and the individual dimensions of each room, that it's really too much to expect the auto setup modes to do anything well with subwoofer setup.
So it's best to ignore that part of the auto setup. As far as the auto-EQ functions, they may be effective for crummy non-linear speakers but usually make things worse if you are using neutral linear speakers like Axioms.
Regards,
