could someone provide me with specific web-sites that have descriptions of the tests that demonstrate the (invariable?) non-directionality of sub-80hz frequencies? i keep hearing about this as a particular sonic property of bass the existence of which has received "scientific proof". however, i have seen claims to the contrary - namely that bass can be localized down to 50hz. while i recognize this could be due to audible harmonics or other secondary audible cues (speaker-enclosure noise, rattling, etc.), the claims of this sort haven't received any comprehensive support either... so i'd be very interested to see the methodology and the results of the various tests i keep seeing mentioned, or any relevantly similar experimentation... thanks.