Shifting the phase (inverting the sub) has nothing to do with the frequency parameters that the sub is designed to perform within.
Shifting the phase can also be done by switching pos and neg
Most higher end headunits allow you to do this from the drivers seat now.
Believe it or not (and I agree about your "crap" rating), Tweeter, etc, a higher end audio store, actually carried the Sony Xplod line. MISTAKE,lol
A-Bahn has always made subs that perform very well in their price range. I owned a set of Aluminum 12's sound Q subs. Well,,.....sound Q subs that could handle 1000 watts of NOMINAL power. Crazy value in that sub.
For that matter (not so much car audio), Sony has also made plenty of quality products. I'm just saying,...what are they thinking associating these terms with electronics??? I just find it all funny