No frills comparo here, I have the UM3x on loan from a fellow head-fier so I figured I'd do a comparison. Most of my testing is done listening to Shpongle, it's pretty much the most taxing music I could imagine for putting headphones through their paces: Posford and Raja Ram cover the whole frequency range a million times over with vocals, instruments, and a slew of different effects, and make by far the greatest use of spacial and imaging characteristics of any music I've ever put through IEMs. As I type this intro I am listening to Are You Shpongled, but I will switch to different albums and will throw in a few others from select genres.
I have the SM3s in right now. I will say right off the bat they are my favorite of the lot, I am hugely biased towards them over, well, really anything else, IEM or can, portable or full size, that I have ever heard. I prefer them SQ wise to many full size and open cans. To me they just have the most magical imaging and convincing presentation, everything else sounds like it's just missing something when I compare. The nicest phones I've heard would probably be the HD598, and personally, I prefer the SM3s. I find no details missing, the presentation is not as open but the imaging feels just as good and the dynamics are, IMO, even better.
But I have always been curious about the UM3x, so I arranged a swap with a fellow Head-Fier; he had my SM3 for a while, and now I have both the SM3 and UM3x. There are a few things I am really impressed with on the Westones. The build quality of the Westones is completely untouchable by anything else I have seen and felt in the class. It outstrips even Westone's own W3 in my opinion, but I guess this should be no surprise as the UM3x target the professional market
Also the timbre of the UM3x is outstanding in my opinion. They do a great job of not coloring the sound; they are very clearly biased towards the midrange, but overall I would say they sound more "flat" than anything I've heard; the HD280 is close, but they are on the bright side of things, whereas the UM3x is more towards the dark side.
The main thing I notice when listening to Shpongle through the UM3x is how much more easily they sound "crowded" than the SM3 or TF10. SM3 does the best job of keeping everything separate and in it's own space, in my opinion, and this alone puts it in a different class of SQ than the UM3x. The TF10 also keeps things separated, but not with quite the same feeling of pristine discreetness I get from the SM3.
With Shpongle, there are times when stereo imaging is really used to the fullest. The tracks Monster Hit is probably the most noteworthy of any I've heard in this listening session. There are sections where the left, right, and center are very clearly separated and with the SM3, you can hear all 3 parts in their own coherent, separate space. It's really pretty amazing, I never really expected anything like this from in ears. The SM3 is truly a gem in the sound department; I have made critiques of Earsonics' build quality, and I hold to those, but when it comes to pure sound and enjoyment of music provided, I really haven't found anything in-ear, portable, or full-size that compares to my ears.
I don't even want to take them out of my ears to do this comparison
Going back to do Monster Hit with the UM3x now. Imaging is still top notch here in my opinion, a step above TF10. The soundstage is bigger than either SM3 or TF10 in my opinion. Unlike the SM3 which is very involving, there is the feel of almost an inner limit to the music that the UM3x produces. It feels much more technical and designed for analytical listening in this sense. The bass that starts dropping around 1:00 sounds a but muddy and maybe even a bit rolled off compared to the SM3, not quite as deep or tactile, more mid-bass I would say. I will say that the timbre of the midrange is fantastic, anyone who is all about the mids will fall in love with the UM3x, I'm sure. The UM3x is great at placing sounds in front of the listener, and on the sides as well; it makes you feel like you are sitting in a quiet room with good, neutral speakers.
For contrast, what I've always loved about the SM3 is that it places me on the stage, like I am swimming in the music and am a part of it. I think the SM3 is better at giving a sense of atmosphere and almost forcibly involving the listener in the music, the placement is not as drastic and noticeable as the UM3x but just as accurate and well-defined. The SM3 sounds sharper, faster, fuller. The UM3x is a more intellectual sounding IEM: you can clearly place everything in your head and feel exactly where it is. This isn't the case with the SM3; you get the sense that things come out of nowhere, and you just kind of get swept along in the current. It is a more involving, less clinical sound. I think the UM3x is the better professional or analytical listening tool, but it is definitely not as fun as the SM3.
There are two big downsides to the UM3x in my opinion. One is the treble. It's a bit of a dark IEM and . The second is the mids: they are both the greatest strength and weakness of the UM3x. They are very detailed and presented right up front where you can hear anything and everything exactly the way it should be heard. Guitars, vocals, etc. clearly stand out from the rest of the sound. However there is some kind of midrange resonance effect that seems to happen when tracks become "crowded" with midrange-heavy sounds and the UM3x kind of loses its focus a bit, almost like it gets confused about what to give greatest precedence to. This effect is enhanced by the slight midbass emphasis, which sometimes gets things sounding a little fuzzy for my taste.
The SM3 doesn't suffer from this resonance. Bass and midrange and very distinct and even when the bass does color the midrange slightly, it's definitely not "fuzzy." It's note presentation is crisper and cleaner overall than the Westones. The defiltered SM3 is also definitely brighter on the whole than the UM3x.
I like strings a little better on the UM3x. They would be better for most kinds of rock and probably most acoustic music, I think, but I prefer Steve Vai on the SM3s because something about the sound is just more immediate and emotional and euphoric, and with Steve Vai it really works its magic. Beethoven goes to UM3x, the cello and bass sound a little fuller, and woodwinds have more air, probably because of the midbass. Vivaldi goes to the SM3, I prefer the violins and harpsicord here. Overall I prefer synthesized sounds on the SM3; they pair really well with electronic music, and Shpongle in particular. The UM3x is better for rap and reggae. Explosions in the Sky have a few songs that really steal my heart and it's just more real and dramatic with the SM3, no question at all - the SM3s really take me there with this song. The rolling drums, the orgasmic eruptions of electric guitar...the SM3s coloration really does it's job here, and the UM3x just falls a little flat for such dramatic music.
So how does this all pan out? If I were a professional musician, I would choose the UM3x without hesitation. In fact I do perform on-stage and when I get to playing venues that require me to protect my hearing, I will probably purchase a pair. The build is extremely solid, the sound is more clinical and easily "observable" due to the inner limit, and there is not the same temptation to get "lost" in the music; au contraire, the sound is imaged and spaced so well that the listener has to give some attention to keeping track of everything that's going on. It's a very focused, spaced-out, intellectual kind of listen.
However when it comes to musical enjoyment, the SM3 is the easy choice for me. It is more colored. There is a texture and feeling of immediacy and involvement and dynamics that just isn't there in the clinical-sounding, slightly spaced-out UM3x. With the filters gone, the treble energy and acuity has really come to life and showed me things I had no idea the SM3 was capable of portraying. Gone is the spaced out warmth and "veiled" feeling that I had with the original; with the filters, I loved the sound, but I always wanted a little more. I would still
In a nutshell, the SM3 wants me to sit and feel the music run through me, to feel like the music is real and I am there; the UM3x makes me want to close my eyes and appreciate every nuance of intent portrayed by the artist and producer. Honestly I really like both of them, and I wish I could afford the UM3x because it would quickly become my benchmark for neutral sound. When it comes to my preference, I am first and foremost about the euphoria and trance-like state that music can bring me to, and in that sense I'm glad I chose the SM3 for myself, because it "takes me there" better than anything I've heard yet.
Tracks used for this review:
Amanda Palmer - Ampersand
Atmosphere - Panic Attack
Steve Vai - For the Love of God
Joshua Bell - Spring I by Vivaldi
Beethoven - #5 in C Minor, #3 in E flat major, Sonata 14.
Bob Marley - Is This Love
Explosions in the Sky - The Birth and Death of the Day
From "Are You Shpongled"
From "Nothing Lasts...But Nothing Is Lost"
From "Tales of the Inexpressible"