Regarding the issue, whether or not turning off the subwoofer in the Audio menu changes the frequency range of the mains... I just tested this playing some 60Hz testtone:
Mains set to small, crossover to 250, Bassmode LFE:
SW on -> SW only plays the low frequency (Mains get cutt off as expected)
SW off -> Mains now play the low frequency (no longer get cut off no matter if there's a crossover set). It seems it "internally" changes the mains to Large.
Mains set to small, crossover to 250, Bassmode LFE+Main:
SW on -> SW only plays low freq
SW off -> Mains play the low freq
Mains set to large, crossover to 250, Bassmode LFE+Main:
SW on -> Both play low freq
SW off -> Only mains play low freq
Mains set to small, crossover to 40, Bassmode LFE+Main:
SW On -> Doesn't play the low freq, or just a tiny bit since I played a 60Hz testtone
SW off -> Only Mains play low freq
So I learned,two things from this:
1. Turning off the SW (in 2 channel mode) will play all low freq through the mains even if they are set to small and their crossover would normally send them to the sub. That means if I want to take some low freq load off the mains I set them to small, but I'm still able to enjoy 2 channel music without sub and the mains playing full range. I wish this was also possible for multichannel sound... but there I can at least turn the sub down to -12dB.
2. The crossover setting for the mains when they are set to large and bassmode is LFE+Main determines which low frequencies are ALSO played by the sub.
I suppose this applies to all newer Marantz and Denon receivers.
Edited by pmcl77 - 4/4/13 at 12:55pm