Your original hypothesis remains speculative conjecture on your part because you dont have data to show what an F12 would behave like without the servo. Secondly between the 40 to 60 HZ range, SPL was off by 1.3 db at worst which is well within the pack. Once you start going deeper, the F12...
This Canadian list is very poor in Canadian content I must say. Here's a far more detailed list of Canadian speaker companies.
http://www.athenaspeakers.com/ No longer around...
This is on the premise that your receiver identifies having a subwoofer connected to it. Go into the manual setup, select speakers and select Parametric EQ. Go into that menu and set it to THROUGH. This step will ignore any of the YPAO settings. Remain in the manual setup and scroll up to...
Most manufacturers top 3 models provide preouts for all channels and a lot of people have separate amps for the 3 front channels while the AVRs power the surround channels. Im fortunate that none of my rooms were so big that I would tax the power of my AVRs.
Like Frank Dernie pointed out...your biggest source of crosstalk lies with the cartridge on a turntable which is inaudible. Even entry level AVRs best the cartridge by a minimum of an additional 40 db. Comparing inuadibility at this point is rather pointless.
Have you personally heard the effects of crosstalk in an AVR? I have 5 and I have NEVER experienced the effects of crosstalk. Thats just one of those pro seperates camp audiophile myths, convenient to bring up but never physically realized.