My pleasure! I wasn't familiar with the authorities Tyll referenced, but conceptually, the discussion struck me as being right on. Is this the book by Toole that you were referencing? http://www.amazon.com/Sound-Reproduction-Acoustics-Psychoacoustics-Loudspeakers/dp/0240520092
Please cite some concrete sources if you aren't intentionally trolling at this point. You suggested that we "go ask the manufacturers," so I will refer you to the explanation by PJ at Bottlehead in post 9 of this thread: http://www.bottlehead.com/smf/index.php?topic=2362.0 You might also google and read the wiki articles on balanced lines, balanced audio and push pull amplifiers.