Got mine used from sheldaze (thanks!)
 
Packs a very clear, clean and meaty (slightly u-shaped) sound in a very small light weight package.
 
I think I prefer it over all my other sources, except for perhaps my O2 DAC/AMP which is more neutral and a little more spacious but maybe not quite as exciting/fun. It's a matter of preference and genre and not a matter of SQ.
 
Works extremely well and is 99.5 % black with all of my current IEMs/headphones. An extremely faint hiss can be heard when not playing.
 
As of now I don't have any super sensitive IEMs but something tells me it will be black enough with anything you throw at it.
 
Nice with CEntrance ASIO support and sample rates to up to 384 kHz, DSD128 and 32-bit bit-depth. Not that I can hear any difference. Anyway, nice to know I can take it "all the way".
 
The volume wheel is very easy, comfortable and quick to operate, and it's completely free from any scratchy sounds (unlike its predecessor).
 
It looks really cool which doesn't hurt...
 
If you have any questions just ask, and if you wish to know more about me and other sources I have or have had then click here.
 
Thanks!

(This review is dedicated to Music_4321 for his outstanding contributions on Head-Fi)
 
Before I begin I would like to mention that I have no ties to HiSoundAudio or the headphone industry in any way. I’m just a hobbyist who loves music and IEMs.
 
No doubt about it; this is a great sounding in-ear monitor. Definitely hi fidelity! Not just relative to its price but also in comparison to my most expensive IEMs costing more than US $1000 each. However, this is not a neutral reference IEM but instead tuned for a very enjoyable, pleasant and non fatiguing sound and it manages to be so without ever becoming boring or dull. Plus, this is the only IEM in my collection that is able to do some serious justice to my most sub-bass demanding tracks, like for example “Tubular World” from the album “The Songs of Distant Earth” by Mike Oldfield. As a matter of fact, this track can sound a bit boring with my reference phones. However, the Wooduo 2 is not a bass monster. The bass is well controlled, never muddy or bloated.The treble sparkle is just right without any harshness. Overall, this is a clear but not overly bright sounding IEM, and it has a touch of airiness to it as well. The resolution and transparency is excellent. If you prefer a wide soundstage the Wooduo 2 will not disappoint and instrument separation is superb. The Wooduo 2 is vented and probably helps the sound to flow effortlessly. It should be noticed that the impact of the bass is somewhat volume dependent. At low volumes the bass may pass as close to "normal", at normal volumes it is very deep and present (as described above) whereas at really high volumes the bass does sound a bit overwhelming, however still very impressive.
 
Sonically, the Sennheiser CX-300 IEM (approx. US $30)  - which is also considered a very bass capable IEM and one that I’ve used and enjoyed for many years - is utterly outclassed by the Wooduo 2.
 
In comparison to the included olive shaped tips – which are quite excellent - I recommend the T-400 Comply foam tips. All other included tips were too small for my ears. As expected, the Comply foam tips improve the isolation, but more importantly facilitate a deep fit which improves transparency, resolution, imaging, and instrument separation. Not all IEMs benefit from a deeper fit but the Wooduo 2 does. Also, the Comply foam tips add a tad more treble sparkle. I’d expected the opposite, but evidently not so. A word of caution tough; a too deep fit will make the bass and midrange somewhat anemic. You may need to do a little bit of experimenting to find the perfect insertion depth.
 
Midrange instruments and vocals projected in the center of the soundstage tend to sound a bit recessed but crisp. This gives the strings of string instruments a clear (but not unpleasant) bite. However vocals can sound a bit lacking in body, perhaps even a bit unnatural, but not at all to the extent that it’s a problem. However, in my experience this characteristic diminishes with burn in.
 
Midrange coherency is not perfect and can be noticed with center stage solo instruments, for example an acoustic guitar. It can on occasion give an impression that upper midrange and lower midrange notes come from two different guitars with slightly different resonant bottoms. This may sound as a serious problem, but it really isn’t. It’s really just noticed if you have trained your hearing, focus on coherency, and have a more coherently sounding IEM to compare with, such as for example the FitEar ToGo 334, which costs approximately US $1.350. Again, this characteristic seems to diminish with burn in
 
Instrumental music (Kraftwerk, Jean Michel Jarre, Yello, Mike Oldfield, etc.) and the Wooduo 2 is a marvelous match. Opera, chamber music and symphonic music and the Wooduo 2 goes very well together too. Most, but not all concertos sound perfectly fine as well. In my opinion, music having a fast, throbbing and dominating bass quickly becomes annoying with this IEM.
 
The Wooduo 2 is small, light-weight and very comfortable to wear and the build quality is more than adequate. Unfortunately the cable is somewhat noisy (microphonic) when worn in front. However, it can also be comfortably worn behind the ears despite its cable being flat. This practically eliminates all cable noise. To make the cable stay in place behind the ears I’ve placed a rubber band just above the Y-split. The rubber band can then be adjusted by rolling it up and down on the cable. It may not look so great but it actually works pretty well and better than I thought it would.
 

 
Now - a week later - I’ve found an even better working and better looking solution by using a piece of plastic-wire, the kind that is commonly used to wind up cables in packaging for electronics.
 
 

 
I’m afraid the build quality isn’t quite what I felt it was initially. While changing tips I held on to the rosewood part and it separated partly from the metallic nozzle part forming a small gap. However, I could easily clue it back with a small brush using some super glue. Fortunately it had no negative impact on the sound as the driver sits safely inside the metallic nozzle part. Since the super glue is stronger than the original glue it won't happen again. Nevertheless, when changing tips I recommend holding it in the nozzle part.
 
For the price this IEM is a no brainer that I highly recommend, especially for those tracks that crave a deep, impactful, yet well controlled bass.
 
Thank you for reading this review. If in any way it was useful to you, please give it a “thumbs up” or otherwise let me know. Thank you!

[size=medium]This is the first review I've ever written about anything, and although there are already many good reviews out there, these IEMs are so special to me that I feel I owe it to the head-fi community to write my own review. I should warn you that this isn’t an audiophile’s review, but rather about what I feel the EarSonics SM3s bring to my musical experience.[/size]
 
[size=medium]Before getting to the core of this short review, I'd like to give you some background on my way of thinking. I love great music. But what is great music? The answer, of course, depends on who you are. To me, great music is sound waves that give me an emotion so strong it often creates a physical reaction. If it makes me smile, if it makes my eyes fill with tears, if it makes my body dance, if it makes me feel I'm flying, if it gives me goose bumps, or what not, then to me it's great music. So, do I need great equipment to enjoy great music? Certainly not! I can enjoy great music in mono from a $10 transistor radio. However, the EarSonics SM3s certainly amplifies the musical experience, to say the very least. These IEMs are nothing short of magic. It feels like these IEMs take possession of the eardrums and integrates the sound with the brain. Everything is there, every little detail, perfectly portrayed. The separation of instruments and voices is so good I can easily choose to listen to any voice separately, however subtle. Yet, I can just as easily enjoy the entirety. Magic! Perhaps the biggest difference between these IEMs and other headphones I have is that they always make me forget that the music is electronically reproduced.[/size]
 
[size=medium]With these IEMs I am rediscovering my album collection. I keep hearing myself thinking things like: "Aha that is the true timbre of his or her voice." and: "Oh, I never noticed those subtle trumpets in the far right background before."[/size]
 
[size=medium]Another funny thing is that they seem to reduce the time length of music. The reason, of course is that the sound is so unreservedly enjoyable. Even when I really haven't got the time to listen to music, I keep hearing myself thinking: "Just another minute" over and over. This seldom happens with poor equipment.[/size]
 
[size=medium]As I already told you, this isn’t an audiophile’s review so I won’t go into details about bass, mids, treble, soundstage, separation, etc. Let me just put it this way. To my brain, the SM3s sound perfect, as close to live sound as I have ever come.[/size]
 
[size=medium]I should mention that I usually connect my SM3s to my portable amp, the TTVJ portable slim. However, connecting them directly to my iPod/iPhone works really great too. The quality is still there, but with a sound signature that is just [size=small]slightly different with some songs[/size]. I.e. you don’t need an amp to really enjoy these IEMs. The TTVJ portable slim is a great amp, and I highly recommend it, but that’s a different review.[/size]
 
[size=medium]Would I have written this review after my first twenty minutes of listening? The answer is a very definitive no. My experience is that the SM3s need burn in (and possibly the brain as well), in my case 10 to 20 hours to become enjoyable, and another 50 to 100 hours or so to get to their near full potential. It’s probably imagination, but I think they are getting a little better every time I use them. I guess I've used them for a couple of hundred hours or so by now. To be sure, the first time I tried them, I tried them with the comply foam tips and was utterly disappointed. Absolutely nothing felt good about them. Even the thought crossed my mind that I somehow might have been conned. Later I switched to the silicone double flange tips and thought the sound was now ok, perhaps even a little better than my $60 (or so) Sennheiser IEMs, but not much. I decided to plug them in to my iPod, but not into my ears, and let them play for about some ten to fifteen hours. I then tried them on again, and what do you know, the magic was starting to emerge. [/size]
 
[size=medium]About the only thing that I find a tiny bit cumbersome is fitting them into my ears. My ear canals are absolutely dry (never heard the word earwax) and a bit narrow. So I always use a tiny bit of lubricant on the silicone double flange tips. As experienced IEM users already know, fitting the IEMs properly is absolutely 100 percent crucial. This just can’t be stressed enough. I’m considering ordering the custom ear molds from EarSonics. Hopefully, in my case, I then won’t need the lubricant.[/size]
 
[size=medium]These IEMs enrich my life. If you can afford them, buy them, and with some patience and burn in, you'll never regret it.[/size]
 
[size=medium]As I live i Europe, do note that the price paid includes European tax and shipping costs.[/size]
 
[size=medium]For some reason, and though it isn’t really relevant, I’d like to finish this review with a quote by Mike Oldfield: [/size][size=medium]“I don't feel I'm a musician. I create sounds that are reflections of my emotions. To be a musician is something quite different.”[/size]
 
[size=medium][size=medium]Update December 15, 2012.[/size][/size]
[size=medium] [/size]
[size=medium][size=medium]512 days have passed since I wrote the above review. So, am I still as enthusiastic about the SM3 as I was then? Yes, and even more so! Since then I have also invested in Earsonics’ flagship, the EM6. In comparison, the sonic aspects of the EM6 outshine the SM3 in every audiophile term I can think of. They simply play in different leagues.[/size][/size]
[size=medium] [/size]
[size=medium][size=medium]Nevertheless, the SM3 gets the most of my ear time, and for two good reasons. The first reason actually being one of its characteristic sound aspects. The SM3 is quite often "accused" of having a slightly veiled sound. In my opinion this is true (especially when compared to the EM6), but in my opinion this is for several reasons not a bad thing.[/size][/size]
 
[size=medium][size=medium]First of all, this slightly veiled sound somehow gives all music a mellow (rich, luxurious) sound. The SM3 simply sounds very “expensive”, very Hi-Fi. Also, this feature eliminates listening fatigue completely. At moderate volume levels I can use the SM3 an entire work day. The slightly veiled sound also conveys the feeling that the SM3 has “more to give”, like listening to one of the world’s greatest violinists, Jascha Heifetz. Heifetz always played in a very high tempo, faster than any other violinists, but at the same time his playing was very relaxed, like he could play even faster (and maybe he could’ve). As listener this makes you feel very relaxed and able to focus on the music, rather than having to fear that something might go wrong because the performer is on the edge of his ability. The same is what the SM3 will do for you, that is, make you feel very relaxed and trust the SM3 performer. It will play (almost) anything thrown at it with ease and make it sound fantastic! The EM6 on the other hand will reveal every possible detail in the recording, and trust me, although this is the goal of the audiophile, it is not always a good thing, especially so with not so great quality recordings (although having great music). If your goal is simply to enjoy great sounding music in one of the best possible ways, the SM3 will do the job effortlessly. The sound signature takes some time getting used to, but once you do, you will hear and sense the golden liquid pouring out behind the veil.[/size][/size]
[size=medium] [/size]
[size=medium][size=medium]The second reason to why my SM3 gets more listening time is that it is a “Universal In Ear Monitor” (UIEM). As such it is much more flexible than acrylic customs (i.e. my EM6), and isolation is really good too. This means I can use the SM3 lying flat on my back in bed, or half lying in a comfortable armchair, which are my favorite positions for listening to music. Doing so with acrylic customs just won’t work, as doing so changes the anatomy of the ear canals and consequently changes the fit and sound of the customs. I find this to be a major drawback with CIEMs and the reason I prefer UIEMs.[/size][/size]
[size=medium] [/size]
[size=medium][size=medium]One thing I no longer completely can stand for is the name of this review: “As close to live sound as I have ever come”.  If I had written this review for the first time now, I think I would have named it: “[size=11pt]The most pleasant sounding IEM I've ever heard[/size]”.[/size][/size]
[size=medium] [/size]
[size=medium][size=medium]I must also mention that the bass of the SM3 is very engaging. I sometimes lack this in the EM6 which is a lot more neutral. One good example is the bass wind instruments in “Act I: Scene 3: The Window of Appearances” from the opera “Akhnaten” by Philip Glass. When heard with the SM3 the bass reaches my soul, whereas with the EM6 the bass wind instruments just reach my ears, although in all honesty, with extreme realism and precision. (By the way, Akhnaten was a pharaoh, known as “the rebel pharaoh”, in ancient Egypt, which by the way I have just visited. If you want some deeply fascinating history, see this video and then also listen to the opera.)[/size][/size]