Re: Will flipping subs around so magnet is on outside hurt them?
That will work. If you don't change anything else, you'll be out phase with the rest of your speakers, though. Being out of phase doesn't hurt anything, but it won't sound as good and may not be as loud as being in phase.
To fix phase:
If your amp has a phase knob, set it to 180. If not, you'll want to swap the positive and negative speaker wires from the amp to the sub, so that the sub is pulling backwards when it would usually be pushing forward.
SounDrive Custom RCAs • High Output Enclosures