TLDR;
Cons: The tuning is so damn weird, they're the antithesis of neutral audio engineering gear. Picky with the kind of music played through them.
Pros: Dynamics when you feed them power, that planar magnetic resolution.
If there was one sentence I would use to describe the MM-100 it's that they have their own reality distortion field. The best example I've found of this that is quickly reproducable are the rim hits in the opening seconds of
Love Came Here. With an LCD 3, this is a sound that is somewhat in the background to my right, and with the MM-100 they are almost up against centre but what really throws me off is that it gives me the impression that the pitch is actually lower - or at least that this rim shot sound has more emphasised lower frequencies than it should have. The MM-100 is so strange that even my HD 6XX has more in common with the LCD 3 than the LCD 3 has with the MM-100. This is definitely a tuning speciific to Mr Manny M, as the LCD 2, Mobius and Sine are also more in alignment with the LCD 3 and the classic Audeze house sound. I haven't heard the MM-500 or the LCD 5, so can't comment on them.
@squibble's measurements seem to corroborate my experience. The MM-100s will tell you in no uncertain terms that they are mids
HEAVY and that chunk dug out of the presence region makes the soundstage sound both closed in and contradictorily also spread out more due to parts of treble getting psychoacoustic emphasis. I'd say this was to counter the classic closed in Audeze sound.k It's done in such a way that it still suits modern synth saturated music but play enough music that you know well with real life instruments playing (or not) and the deviation is stark.
Bhaskara's Wheel is a well recorded modern jazz track that I've used forever as a reference for natural cymbal hits and tambourines - the MM-100s make them sound artificial.
Bubbles sounded so wrong compared to the other headphones and my stereo rig. Epic trance/future rave tracks like
Satisfaction lose their epic scale.
In fairness, the clarity and resolving ability is befitting of what you expect from planar magnetic drivers. And when the song isn't messed up by the weird tuning, this is clearly demonstrated in vocals.
What Was I Made For? has an apt focus on Billie Eilish's breathy voice, bringing out the subtle details and clearly separating each part of the mix. And if you continue to listen to the MM-100s it is possible to adjust to the sound and forget about everything that you know about how things should sound. It is possible to be immersed in this sound with the right songs and a bit of a lucky streak.
I think of this as a headphone editorial, tuned to subjective preferences, which is perfectly fine in its own right. What rubs me the wrong way about this is that they are marketed as a professional studio/mixing headphone. I shudder to think of the resulting tracks produced on them.
Will I keep them? I don't seem to be able to get rid of any of my Audeze gear, being the constrained fanboy that I am, so they'll stay. But I really doubt that I will listen to them all that much, being an audiophile first audiophile.
Would I recommend them to my friends? Nope.
edit: PS. Probably a huge deal breaker for people who haven't pre-ordered and are looking to get these. There are only 3 adjustments for the head-band. I'm lucky to have my big head fit the loosest setting.
