Hi,
I'd put it another way: Bass starts to localize acoustically at frequencies higher than 80 Hz. Or, at 80 Hz and below, bass is not easily localized in most rooms.
Of course, if you have mechanical vibrations from a good subwoofer that travel through the wooden floor or frame of your couch, as it sometimes does with my EP500, which sits next to my couch, then mechanically the bass is sort of localizable, but most of the time I've found that 80 Hz is generally excellent as a crossover point.
You do have to experiment, as room resonances and standing waves pile up in every room rather differently, but 80 Hz is a very good starting point.
Regards,
Alan
