The equipment used:
iPod Touch 2G → FiiO L9 → Arrow 12HE 3G → UM3X RC or SM3 v2. The Bass setting on the Arrow was set to "1" (which is my typical preferred setting). Cross, Impedance and Gain were set to "0" for those scoring at home.
After trying all of the factory Westone and EarSonics tips on either set of earphones, as well as a small selection of random bi-flanges, tri-flanges and Etymotic foamies my ears seem to agree most with the Shure Olives. As an equalizer, the Shure Olives were used on both sets of earphones for this test.
I chose five different tracks from different genres to fully test the sound characteristics and frequency capabilities of both earphones. The next few paragraphs are the (sometimes rambling and incoherent) notes I took while listening to the various tracks with each set of earphones. I intended to use these notes for the actual review. But, after re-reading them I felt like I couldn't get a more honest accounting than what you see below. Enjoy...
Smashing Pumpkins - The Rose March
SM3 : Slightly recessed guitar, intimate sound, upper vocals slightly veiled, sound stage average (not great). No sibilance. 1:35 bass guitar kicks in, slightly muddy, feels crowded, cymbals have a nice hit (more impact than the UM3X). Can't get past the muddy nature of the bass, almost overpowers the track. On the whole, not a bad experience, but certainly less-than-great.
UM3X: Guitar intro (in your face), very intimate. vocals are crystal clear. Better separation of instruments and vocals. Can easily see everything in their right space in my mind's eye. Lush vocals and mids. No sibilance (similar to the SM3). Much clearer vocals. Bass has slightly less impact but comes through much clearer, does not over-power. Cymbals have slightly less impact (every-so-slightly more veiled than the SM3). Everything feels less crowded. Much more enjoyable listening experience.
Radiohead - High and Dry
SM3: Opening of the song is a kick drum is a couple of bars of a heavy kick drum and cymbals (with slight echo which is reproduced nicely). Nice separation, but these frequency ranges are the SM3's biggest strengths. Good juxtaposition of high vs. low. Guitar comes in, less impact than drums. Mix feels off (due to slightly veiled mids). Too much focus on drums, guitar lost. Now the vocals come in, same thing. Details are still good. Slightly sibilant. Average sound stage, a mix of intimate and spacious.. Likely due to a heavy use of an LFO in Radiohead's mix. Good headphones for a song like this.
UM3X: Missing some of the upper-range detail that the SM3's had with the opening drum sequence. Vocals come in. AMAZINGLY intimate! Lush, warm, inviting mids. Better vocal detail. Thom Yorke is "in your head," kinda creepy by fun. [edit: I thought about removing that line, but I still LOL at it.] With the SM3s the drums felt like the focal point of the song, and the mids lost their place. Not so here. The mix feels more balanced. Sound stage is smaller. The LFO effect feels less pronounced. Less fatiguing.
People Under the Stairs - Acid Raindrops
SM3: Steel drum loop at the intro sounds great. I can pick up the slight reverb effect that I never noced before. Trebel centric feel. Mid bass is more pronounced than the low bass. There are low frequencies that I know are there, but they roll off with these. Normal feel and vibe for a Hip-Hop track. Slightly sibilant highs. These might be a bit fatiguing with a longer listening session.
UM3X: As I listen to my Hip-Hop collection with the UM3X I begin to realize that I am focusing on the lyrics more than the soul and vibe of the track. The UM3X is subconsciously forcing me to pay attention the vocals more than I usually do…. and this isn't a bad thing. I often get caught up by the beat and focus very little on the track. Snare drum is hitting hard. Cymbals are slightly recessed. In some ways, the mix feels lightly off from what my brain thinks it should be. A good experience, but far from the Sennheiser/Ultrasone sound that I prefer when listening to Hip-Hop.
Royksopp - This Must Be It
UM3X: Heavy treble-centric track, but it is non-fatiguing like it can be with other headphones. Kick drum has a nice fast pace to it. As the mix gets more layered I don't lose track of the different parts in the mix. This is a very hard thing to accomplish with a Royksopp mix because there is a tendency for the track to get crowded. As stated before the vocals are lush. heaviest layers come at 3:10 and it still does not feel crowded. Wow. I'm now hearing details in the distortion (intended) at the end of the song that I have never heard before. I Like!
SM3: Feels thin, boring, treble-centric. Vocals are thin, less body. My attention keeps being brought back to the cymbals and misc. high frequency electro-synth-bits. 1:24, as mix gets more layered, it doesn't feel crowded, but it's more dynamic. I can't fine the groove, my attention is diverted by all of the dynamic movement of these headphones. It's rather like trying to see which frequency range is going to win on the battle of who has more movement. If you want to feel uncomfortable with the feel of the track and a bit dynamic, this is the headphone of choice. At 3:10 as the track has the majority of its layers I am hearing the strings with better authority and detail than the UM3X. Overall, these headphones have better attention to the upper range and this track needs that attention. All of this chaos is a good thing for this genre. The SM3 seems to be winning for Electronic music in my opinion.
The Shins - Saint Simon
UM3X: Vocals come in with a warm sense of authority. Cymbals and guitars play a nice accompaniment to the lead singer as it should be. I'm hearing a better interplay with the lead singer and the backup singers, more so than other headphones I have listened to with this track before. Cello sounds great in this track. Warm, inviting and intimate. I nice counter-play to the vocals; Neither one battling for supremacy. Something I do not remember hearing consciously before.
SM3: I hear more reverb on the lead singer's voice, likely because the upper range is more revealing with these. High-hats and cymbals play a more prominent role and seem to be battling with the lead vocals (a little distracting). Strings are sweet, but are overpowering in the mix. This track feels less intimate due to the recessed vocals. With these headphones I would almost rather the track be instrumental.
I've been an amateur producer of instrumental Hip-Hop and Electronica beats for many years and my subconscious attention to detail is typically towards the far extremes of the frequency spectrum, leaving out the middle. Because of this I have always felt more comfortable listening to headphones with a "V-shaped" sound signature. I did not realize how much I have been missing in the mid-range until I had purchased the UM3X. I still prefer a slight "V-Shape" signature with most Hip-Hop and almost all Electronic music, but that is not all I listen to.
My musical influences are quite broad, as I sample from just about anything that can provide inspiration for my music. Oddly enough, more than half of my musical inventory (CD, LP and MP3) is Rock, Alternative, Jazz, Funk, Soul and Other. With most of that music the UM3X seems to be the weapon of choice.
I would say that the SM3 well is suited for all of my Hip-Hop and Electronica music, but I would be wrong. When I wanted that dynamic punch that left me feeling a little uncomfortable I would grab the SM3s, rather than the more distinguished and laid back attitude of the UM3X.
Which is better? Neither.
For those looking for a different answer than that, I am sorry to disappoint you. They are different headphones with different purposes and different vibes. The UM3X does amazingly well with long listening sessions. They have zero fatigue and have an uncanny ability to create an immediate sense of warmth and intimacy that I have never heard in a headphone. I only have the budget to keep one of these, which means that SM3s are going back while I am within the 30-day return window. Currently I am looking for a headphone that will allow me to spend more time with my Rock/Alternative music, which I have been neglecting for a long time. The UM3X will also double as great Hip-Hop headphones when I don't desire a loud, in-your-face approach. At this time the UM3X will do more for me than the SM3s can. I would certainly keep both if I could.
I may buy the SM3 again, or I may not. In the end, I am very happy to have the UM3X in my stable of great headphones and the SM3 will be missed.
Update (9/18/11): I have been experiencing intermittent sound loss in the left channel of my UM3X RC, likely due to a faulty cable or connector. After only a week of use this concerns me greatly. I requested an RMA from the company I purchased them from. Call me crazy, but I may replace them with the SE535. We'll see.
Major Update (10/5/11): My SE535s arrived a week ago. After about 30 hours of testing and many-many tips I'm very happy with these! I think the Olives are the 2nd best option for the sound signature I'm looking for, but oddly enough the factory EarSonics bi-flanges that come with the SM3 v2s sound best with the SE535. The bass and mids are unchanged compared to the Olives, but the Treble has slightly better extension. It may also be placebo, but I think there is a more open sound to the flanges. They sound great.
The build quality is absolutely amazing. There is also better instrument separation than the SM3s (although not as good as the UM3X), but the mids are not as pronounced and unrealistic as the UM3X. Bass is VERY detailed and extended, but not as strong as the UM3X or the SM3 (OK, the only negative point). Less rolled off in the treble than both the UM3X or SM3. They're great! I'm a happy Head-Fi'er.
Edited by SoulSyde - 12/11/11 at 6:22am