Hi all. This is my first time writing a review/critique of a set of cans, so bear with me for not having impressions as technical as most people. But maybe that will help some other more novice audiophiles who also don't have the language to describe some of the nuances in technical terms.
First some details...
1. I bought the Audeze MX4s B-Stock last weekend. I honestly have no clue why these are B-Stock; I can't find a blemish on them. The closest I can find is that the cable connectors (on the cable) have some small dings in the plastic.
2. I've so far spent about 8-10 hours listening, and have been running music/break in tracks on them (white/pink noise, frequency shifts, etc) for probably 30-40 hours total. Definitely a noticeable difference from right out of the box, so excited to see where they end up.
3. My set up is: Tidal (Master) or DSD library (up to DSD256) running off of PC or mobile with Audio Player Pro. Runs through a Schiit Wyrd, then Audioquest Jitterbug (not sure these are additive, but I have both, so why not), through to a Pro-ject Pre-box S2, and finally into a Schiit Lyr 2. I have been tube rolling quite a bit and have also tried them with the LISST fully solid state arrangement. Cables are Audioquest Carbon, Shunyata Venom, Audioquest Columbia 72V DBS.
4. I have also run these straight through to the Pro-ject and through my Chord Mojo. I have a DFR, a NuForce DAC80, and a (budget) turntable, but have not paired my MX4s with any of these yet
5. Other headphones in my repertoire: Audeze LCD-2 (fazor), AKG N90Q, AKG K712 Pro, LZ A4, AKG K553 Pro
6. Music listened to: most genres. My DSD tracks are mostly Jazz, Folk, and Classic Rock (plus Thriller). Through Tidal, I run most of the gamut, with the exception of much metal or dubstep. I've spent a lot of time with these listening to jazz, classic rock, hip hop/rap, electronic, nudisco, folk, classical/orchestral, contemporary rock, some EDM, probably in that order.
Impressions...
Sound Dynamics
Apologies in advance if I've placed any of these dynamics in the wrong category. I've tried to include examples of instruments wherever possible to help explain my point.
Bass
The bass has really nice extension and texture. How low the bass can cleanly reach and the realism of the timbre demonstrated both seem to vary a lot tube-by-tube or depending on the amp. I would say the depth reached never disappoints, but the tightness and realism of the sound reproduced varies. This includes the bass "slam," which I would say is usually on the light side, but can get to a point where you can feel the air moving like a light pressure on the head with the right tubes. Basshead cans, these are not. I would describe the bass as best in line with the tone/texture of a bass drum from a short distance, more so than nearby a subwoofer. It is tight and can be full, but does not really hit you hard. Stand up bass can sound vividly real in tone and reverberation, but sometimes lacks the hollow roundness that comes from the instrument's body (I find this the case with all the HPs I own). Drums can, and often do, sound absolutely amazing. Here the hollowness shows through and you can practically feel the contact then the subsequent reverberations as the cover tightens.
The detail reproduced in the bass, and that ability to extend clearly, make all genres I've listened to enjoyable. Even with more electronic/EDM music which have heavy bass allow you to experience the low extension. It just more often lives more as a tonal reproduction or a slight vibrational impression rather than a real weighty, hitting thump. The one thump most often felt it with drums.
Mids
Disclaimer: I typically have a harder time evaluating mids. I don't know why. I will say that with these, the lower-mids/upper-bass and the upper-mids/lower-treble sound fantastic to me. Some of the stuff that appears smack in the middle, particularly male vocals (pardon me if that's not considered properly middle of the spectrum), I find can get lost and/or sound veiled. The trombone, which I consider lower-mid into the true mids sounds astonishingly good. Certain tracks can cause me to physically tense up when a trombone is really wailing. Actually, in general, I'd say all the brass I've heard through these is really special. Jazz isn't typically my most-listened-to genre, but these headphones make me want to hear more of it. As said, male vocals can sometimes feel recessed, particularly when there are lots of instruments going on simultaneously (more on that later). The guitar, the one instrument I play, sounds very real in its reproduction. Pull-offs, slides, even minor vibratos are all faithfully reproduced. I've heard plenty of details I've never caught in tracks. Piano to me may not have quite the same realism as brass, but it's still typically shockingly good versus what else I've heard - reproducing in great detail both swift moves around the keys as well as the pressure applied to each key. You can follow not only both hands, but often the fingers as well. Female vocals can be visceral, are generally more forward than their male counterparts, and can have an emotionally moving realism about them.
Treble
The music I've listened to probably has had less treble focus, especially in the higher(est) registers. Continuing with female vocals, when really belting, the highs can come across a little sharp, but I'm not sure any more so than in real life. It's raw, maybe even harsh, in a way that's totally enjoyable (in the short moments those notes are held) because of how it elicits emotion and strain at those high registers. Drum's cymbals can similarly be a little piercing. And, again, I find it pretty reflective of the real life experience. The same goes for violin, though I haven't listened to a ton of music where the violin is especially highlighted, nor where the violins live in their highest registers. Things like hand claps ring true, hitting with a proper, feelable, slap. Highs in general appear nicely balanced and generally pretty transparent without being too airy.
Overall
The sound is very balanced, to my ears. It also often sounds very real. The relative demonstration of various ranges is about how I would expect them to sound in real life, except perhaps for vocals (particularly male) which can seem recessed/veiled. Even so, there is an inherent musicality to the way the MX4's reproduce sound that makes me want to keep listening.
Sound Staging & Detail
The sound is incredibly detailed and precise, but it's in a way unlikely any other headphone I've heard in terms of staging, separation, and presence. As others have commented, these have a more intimate feel, almost like a closed-back or semi-open-back headphone. Comparing them to the HiFiman HE1000 v2's which I demo'ed a few months ago, those felt muuuuch more spacious, open, sweeping, almost airy in their separation and soundstage. Here, it sounds like all of the action is within a more confined space, probably defined as slightly larger than your head. Yes, there can be faraway sounds, but these typically present as a brief interjection (like the wood block or cowbell, or whatever that is far off to the back right in Thriller) than anything actually emanating from a space that feels far away for the duration of a track. But, at the same time, these have a strange, almost hypnotic or transcendental effect on me. When really focusing on it, it doesn't seem like there is a ton of space in which the sound lives. But at the same time, they have this uncanny ability to dull my other senses, and sense of self, so that it feels like the space of the sound is basically all the space there is. It sounds crazy, it sounds weird, but it's a lot of what happens. The first time I demo'ed the MX4 I suddenly came back to the space I was in to realize that I had been staring at (more like through) the wall with my eyes open the whole time. There is so much musicality to the sound that it's like you are transported to the room where everything was recorded. But in your own head? I'm not really sure how to describe it. Intimate is probably the best way. But it is hypnotic. Thanks to the realism of the sound, I often find myself unintentionally singing aloud along with the music.
The three-dimensional reproduction is fantastic. With my LCD-2's I always strangely got the sense most of the music was happening behind me/in the back of my head. It would wrap around, but almost always coming from behind (to the point where I've actually switch my L/R connections before to try to flip the sound). The MX4s really do a nice job with 3D presentation. Width/depth may be a little bit lacking, but you definitely get a great sense for where everything is in relation to you. Live recordings sound especially amazing because you're actually situated in the crowd. In one Louis Armstrong track (DSD) someone addresses the crowd with a joke. Not only is their laughter all around, but you can make out loads of different voices, laugh types, etc. that really place you in the room. In another recording, presumably a waiter trays some glassware and the glasses happen to clink - I instinctively turned my head towards my kitchen thinking one of my shelves must have shifted or something, causing my glasses to bang together, before realizing this was in the room of the recording, not my apartment.
Instrumental detail and separation is great... except when there are lots of instruments simultaneously. The detail never really disappears. Even with a mass of sounds I'll pick up details and "instruments" (you'll understand the quotes in a second) I've never heard in the recording before. Oftentimes I'll catch a fleeting note and be able to pin precisely where in the space it came from, but it's so ephemeral that I have to rewind to be sure I've heard it. While the note/sound are there, the detail of what the timbre of that note, or source from which it came, seem to disappear. On the one hand, it's amazingly impressive that so many distinct sounds can be reproduced with such fidelity at the same time.
On the other, it's disappointing that these can come together as a wall of sound - or a wall of individual notes - whose placement is certain, but whose source is not. I'll admit, this does add to the hypnotic quality of the headphones. You're completely enveloped in sound, like you've plunged your head into a bucket of music-water. And it may even hit at realism - at least in the way it would be experienced through headphones rather than speakers situated in front of the listener. The kind of separation and detail I've heard in other headphones isn't how we really experience music - in a live performance sounds do merge. But with my listening style, I have to say this lack of distinctive detailed separation is, so far, the most disappointing facet of the headphones to me.
Again, I need to reiterate that this is only when there are many instruments doing many things simultaneously, as in an orchestra, big band jazz, or, in some cases, rock music with lots of layers. For more intimate recordings, it's incredibly lifelike and detailed. And, further, the sonic tendencies of the room can typically be gleaned quite well - like a drum reverberating off a wall, or a piano echoing in an open room.
Comfort
Outside of IEMs, these are probably the most comfortable headphones I own. The LCD-2s feels heavy and don't seem to have a size setting that's quite right, either feeling a little loose or sitting a little high on my ears. I actually almost never listen to them except lying down as a result. The AKG N90Q's are also quite heavy and the style of headband, while comfortable for an hour or two starts to put a lot of pressure directly beneath it in longer listening sessions (I got these to use on planes and in the office). The K712s are heaps lighter, but the headband never seemed to offer enough resistance/the cups didn't clamp enough for them to feel like they were staying put in the right place - they always felt like they were slipping down my head. The MX4's floating and broader headband really seems to disperse the weight well and makes them feel much lighter than they are. They also have enough clamp. They don't add a lot of pressure, but they'll definitely stay put. You can dance/jump around in these things, and, depending what you're listening to, you may find yourself doing so without meaning to thanks to the liveliness and realism of the music.
Conclusion
The comfort, coupled with the incredible sound, make it difficult to stop listening to these. Really. I have to pull myself away. Like a Netflix binge, I find myself saying "one more song" over and over again until an hour - or more - has passed. It's an endless rabbit hole of "wow! That sounded amazing, I wonder what this song sounds like. Then I pick up something else and on I go. Or I just throw on an album or playlist and get completely lost in it. The only real criticism I've had, and the only thing that would make me question if these were worth the ~1,600 I paid for them, is the way the separation and spacing come into play when there are many simultaneous players on a track. Other than that, these are a joy that provide the escape from this world music is meant to in a way unlike anything else I've spent time with.
If anyone has any questions, or wants more details on comparisons (between headphones, DACs, tubes, amplification, whatever), just reach out and I'll happily do some A/B testing when I have time.
