Ok guys, just as I promised I going to write for you some sound impressions of my UM-3ways.
I listened to them through iriver iMP-550 cd player, which I consider to be one of the best sounding source. It has quite dynamic yet natural sound.
To start with, IEMs were made based on Knowles CI22955 drivers dedicated woofers and TWFK as a mid and high freq driver. UM put everything together and made crossover.
Build Quality
What can I say more... These beauties are flawless. UM is known from its craftsmanship. And it was already stated many times, that it's one of the best in the world. Acrylic is surprisingly clear and shinny. I can hardly see any bubbles.
Inside the shell there're lots of litz wires coming out from resistors and cap which make 3 way crossover.
It's worth to remark that UM has made sound bores that is typical for Mages. Dual-bore with 1cm single-bore sound outlet.
Fit
As I have already said fit is quite good. It seems like right earphone doesn't seal as well as left, but I've found out that it depends on how I put it in ear. I don't loose seal when moving head or mouth so I don't see a need to get refit, it's a nice surprise. When we are talking about isolation it's about good. I expected it to be more than comply foams but it's kinda the same. It's better than PFE with stock silicones though.
Earpieces are quite heavy. But they totally disappear in ears. I can wear them whole day 
Sound
Well, UM3w are vary neutral IEMs. There's no colorization in sound. They sound pretty balanced with lows going to the very 20Hz. The attached frequency graph shows 20Hz-20kHz +-30dB but 20-13kHz +-10dB which is still impressive. Notice how UM3w's graph is similar to Mage's.
They're very efficient 118,49dB@1kHz and only 19 Ohms DC resistance make them easy to drive but they also tend to hiss.
Highs: To be honest, after reading how TWFK driver is great on highs, I expected more in this department. Though I'm not saying they're bad either. Highs are present and well extended. But hey Audeo goes waaay farther and has more sparkle. I really got used to PFE trebles and really like them so I don't consider UM3w to be best of the best. Nevertheless UM3w has enough treble to enjoy rock, jazz or classical.
Mids:Very well presented. Midrange is close but not Westone UM1 intimate. Vocals are in front of listener. They are sweet and soft, I've found their bests with female singers. Guitars sound vivid but don't overwhelm singer. Mids are fairly detailed. That said UM3w do great job with hard rock or even hardcore.
Bass:Looking at the graph you can notice a very flat bass response. This is why UM3w are natural sounding earphones. Though low frequencies are still present. Lows are very very fast, one of the fastest I've ever heard. That said you can hear every single bass guitar or double-bass string. They never overwhelm other frequencies. Bass creates those nice vibrations in your brain and nose. It has good texture but it's still not as good as TF10.
UM3w lows will not satisfy bassheads. Personally I'd like them to be more extended to fully enjoy rock and hardcore music.
Soundstage and imaging is great. Soundstage is wide while deep. It's almost as wide as Audeo's but it has better depth. It makes UM3w sound more 3D.
Instrument separation and overall amount of details are fairly impressive.
Amping It's fair to say that they really profit from amping. When I put them via SuperSimple hybrid they started to shine. Bass stared to sound just as I wanted giving nice and smooth and dynamic sound. Mids got even more lush.
Summing up UM3w are natural yet musical sounding IEMs. My assumption is that they are just between ES3x and Mage in term of sound.
You can really enjoy listening to music with them if you like IEMs with great amout of details while still being dynamic.
UM3w is quite similar sounding to Audeo PFE but with better lows and closer mids. Well... it's something that I was running from. I've hoped to get something that would hit me in the face with bass quantity and extension, but seemed that UM wanted to keep their unique sound signature.
None the less I like them and really enjoy them more and more everyday
Anyway UM did a great job and I wanted to thank them.
see a close up here
Edited by piotrus-g - 11/4/10 at 1:27pm
hope you understand that 
