I wish I knew. I've never compared M100s with passive 1100s. And looking at the curves, like you say, the passive 1100 is better but exactly by how much given the closeness of the curves? Remember jritz though? He claims his 660s are Nirvana. Then again there's Cork who liked the M80HP better than 660s. But that could be because of set-up and listening preferences. But then, the passive 1100 is not a 660, is it?
You could be the first one to compare M100s against passive 1100s and then passive 1100s against active. Imagine the fame that would come your way.
