Can I ask what amp you use with the PM3s?
The reason is that my experience is completely different! I own both PM3 and M100 and whilst I don't find the overall sound signature completely different, I do find the M100 has much more low bass than the PM3. Not even in the same league.
I am using an Oppo HA2 and a FiiO E12, but have also tried them on some home amps.
First, I was answering another guy's question.
Second, I don't have a PM-3 yet but my research tells me that this will be my next headphone purchase.
Third, when I do get the PM-3, I will probably get the HA-2SE.
I own m100 and i like it alot,
i tried pm3 from a friend but only about an hour or something ..
First both of them are very efficient and for me they needed no amping, tried them from my x5 , zx2 and even from an iphone and they all sounded good.
from memory i didn't think they are quite alike, for me the m100 is more of a V signature, but the pm3 was more of a neutral and a bit flat in your face presentation, they sounded cleaner then m100 but the sound stage was very narrow on the pm3 and that was my only problem i guess.
i don't think the pm3 will ever achieve bass of m100.
same as the idea that sz2000 remains the king of bass, but the overall sound quality i don't find it in the league of the m100.
For me m100 is the first step of bassier headphones with very nice quality tending to audiophile direction, if you agree with the term.
thats my opinion, anybody is welcome to disagree though