JohnK,
I don't believe that a good receiver would need to have any 'load taken off'. It should perform equally as well driving a tiny pair of mains set to large or small.
But here's where you and I continue to part ways in opinion.
In reply to:

a good sub, properly set up, should do a better job, even in the 40-80hz octave, than those large speakers, which should be set "small" despite their size..



To say that the sub vs. large mains will automatically be 'better' is a stretch.
A subwoofer, with its rather large driver(8"+), does not produce the same bass sounds as a smaller, lets say 6" driver. Although i do agree that the larger driver can certainly play the lower bass range at a louder volume using less power, this does not mean the sound produced by a sub is any better than large mains.
I for one, as you know, do not like the heavy sound from my EP350 and much prefer the sound of the M60 for the entire sound range especially for music. My sub is reserved for HT applications and the extreme low end frequencies, less than 50Hz or so, during music playback.
Perhaps if my receiver had a crossover at 50Hz (or less), i would set my mains to small and go the setup route often suggested. Until i have a receiver with such a capability, the downward frequency curve of the M60 can be matched pretty well using the internal sub crossover around the 40-50Hz mark.
Just taking a look recently at the frequency measurements for the M80s (best comparison), it appears that my ears have heard what the graphs say, that the M60/M80 start to drop off at the 50Hz level. Therefore this is about the best place to put a crossover for the sub if these speakers are to be set to 'large' within the receiver.


"Those who preach the myths of audio are ignorant of truth."