The Ultrasone Signature Pro's...my second pair of Ultrasone headphones coming from the Edition 8's. I must say I am pleased with these especially for the price I managed to get them for. Listening from a decent smartphone or a MacBook I have to say they are impressive.

BASS
The bass quality is very very good. And in terms of quantity does not disappoint. The sub bass is deep and wide. Higher frequency bass is agile and punchy, perfect for metal (double-bass drumming).

TREBLE/MIDS
A little shy but in no way recessed. The treble and mids sound beautiful. While not as forward/euphonic sounding as the Audeze LCD-2's or as resolving as the Sennheiser HD800's, the midrange displays excellent detail/resolution. IMO these are more close in sound to the Fostex TH900's but with a more held back midrange. The treble is fast and in no way sounds harsh or metallic.

OTHER COMMENTS:

Very good for classical music. And watching movies is a pleasure as well. I enjoy listening at lower volumes too. The bass retains its punchiness and micro details are displayed with great satisfaction. Not a bass monster.

CONCLUSION:

A great all-rounder headphone for every genre of music. Competes with a lot of higher end headphones. Portability is also a big plus.

I have never in my life heard such detailed and powerful bass in an earphone. What's even more unbelievable is that these earphones are incredibly detailed without ever sounding thin like detailed earphones and headphones tend to do in the mid and upper treble. These are the most tonally accurate earphones and headphones I've ever listened to. And the most bass-detailed headphones/earphones I've ever listened to. I can actually hear bass passages I've never instantly noticed before on headphones, but only could hear on good floor-standing speakers. The drums don't muddy up with the bass guitar, but separates wonderfully. Drums actually sound like drums now; they don't sound like a pencil rapidly tapping against a table (LOL). You can hear what it sounds like "after" the drum (reverb). I can actually hear the reverb and feel the ambience of electric guitars. The soundstage is the best I've heard in a earphone so far, besting even some mid-fi portable heaphones. This may partly be due to its vented design, making these earphones semi-open. Wood instruments sound spectacular. The timbre of wood instruments through these earphones is phenomenal. It is not a "all-in-my-mind" mental thing since I already knew they made the housing out of wood and the speaker is wood-domed(I've heard cellos, violins, etc. all my life, I know what they sound like). The Earsonics SM3's and Audeze LCD-2's sound amazing with wood instruments as well, being able to emote the essence of musical instruments; the SM3's not being made out of wood at all. But the FX850's IMO are more tonally accurate than both the LCD-2's and SM3's with more air/tonal accuracy than the SM3's and more smoothness/less grain than the LCD-2's. Lastly, these are comfortable as hell! They fit my ears perfectly with their angled nozzle design to better fit in one's ears. These are what I was looking for in a earphone or as a matter of fact headphone for a very long time. You got to try these people!
PEACE
***Add-on: You will need a very quiet source/amp for these earphones as they are very sensitive and you can hear a faint hissing on sources considered quiet. This does affect the treble response quite a bit to my ears, adding a little grain to it.

Wow! These sound like open headphones!
These are my first audiophile quality earbuds; I've heard about Sennheiser making "high-end" earbuds for quite a while now along with Yuin, Blox, etc. But I never really thought spending over $20 on earbuds was justifiable. But I recently came across a deal on head-fi and got these for $14! They're like over $200 on amazon right now since they are to my knowledge discontinued by Sennheiser. After listening to them for about 8 seconds (Eva Cassidy- People get ready) I immediately was in awe of how full these teeny-tiny earbuds sounded! Eva's voice sounded crystal clear and fluid. The bass is not dominant at all, the midrange is spectacular, the highs are crisp! These made me a believer in high-end earbuds LOL.

These earphones possess a truly unique midrange. They make some instruments (such as the cello) sound better than they actually are. Vocals sound rich and warm with incredible body. These may not win in the "most-detailed" or "most-neutral" earphones/headphones category, but they sure do win in the "best-midrange" one. I am hard-pressed to find any headphone that produces a smoother midrange than the SM3's. I previously owned an LCD-2 Rev. 2 who's midrange was very liquidy and detailed; but they were still not as fluid as the SM3's midrange. These are truly special earphones with a special sound.

Excellent sound quality. I can't find any fault with these except for the fact they have no removable cables. The DN-1000's put to shame any IEM under $300 currently in the market right now. Highly recommended.
 
Note: If there are really two versions of the Dunu's, I think I got the "China" version of the DN-1000's instead of the international version as the treble is very extended.

I am apologizing beforehand, this is not a review but only praise for the Focal Spirit Professionals. Forget the B&W P7's, PSB M4U1's, Sennheiser Momentums, or as a matter of fact any portable headphones that are $300+ or below a thousand something dollars. These are absolutely amazing headphones with absolutely no flaw I can nitpick. As neutral and smooth as they are, they are still packed with fervent energy without the stridency or grain in the higher frequencies. The bass is also very satisfying with great body in the mid-bass and precise rumble in the sub-bass. Moreover, the soundstage is truly impeccable for a closed-back portable headphone. Beautifully melded sound. As a matter of fact these portable-headphones are competitive against some high-end open cans  in my opinion and that speaks volumes. Lastly, I would like to point out that when listening to drums, the timbre is soo spot-on; it reminds me of the HIFIMAN HE-500's :]

Decent. But get the Dunu DN-1000's instead.

I've owned the Sennheiser Momentums, B&W P7's, and other mid-fi portable headphones but I prefer these in terms of sound quality only.
Why? These headphone's have such an organic/balanced representation of all the sound frequencies that it really sounds accurate/natural opposed to accurate/cold or overly colored.
Sennheiser Momentum: Dull/bloated bass response, overly thick midrange, and recessed high frequencies.
B&W P7's: Unnatural Representation, slightly thin midrange, loose bass, strident high frequencies.
Ultasone Edition 8's: They are like $1499. Better than the P7's and PSB's , but severely overpriced.
Bose QC 15: I tried to like them for their excellent noise cancellation but the sound is so horrible.
Sennheiser PXC 450- Dry, dry midrange, subpar bass response, better noise cancellation than the M4U2's but not better passive sound isolation.

I did not like the B&W P5's b/c of their dark/bloated sound but the P7's changed everything! It may be because it's not an on-ear headphone like the P5's that "muffles" out the higher frequencies, I don't know. But regardless, these have an exciting and detailed sound that is very engaging. Some disadvantages the P7's face is its slightly thin midrange, boosted treble, and unnatural representation. The soundstage is great for a closed headphone but that means nothing because the presentation is very unnatural; and it sounds somewhat synthetic because of the boosted treble and flabby loose bass. I'll admit the P7's imaging is great, but the resolution and tonality is nothing special (just because you have boosted treble doesn't mean your gonna have a tonally accurate or a highly resolving headphone/speaker). If you want a portable headphone with a more accurate and natural representation along with a more connected bass and fuller-sounding midrange, get the PSB M4U 1's instead. If you want the best of both worlds, get the  FOCAL SPIRIT PROFESSIONAL HEADPHONES. All in all, these are still one of the best portable headphones currently available.