I have been enjoying PRO 900 for a couple of months and so far I am very satisfied with how they perform. They are as good as bassy phones can get especially considering their price. High-quality and plentiful bass along with crystal clear high are their main strength and there is durability and comfort to boot. As good as they are, they are not perfect and that led me to trying out another pair of phones that seemed like a natural progression from PRO 900. I've read all the reviews and posts about D7000 that I could find. I was quite sure that D7000 would match or improve upon all aspects of PRO 900 except bass, comfort, sound leak, and of course, price. I knew I would always wonder if I didn't try D7000 for myself so with some doubts, I ordered a pair. I have listened to D7000 exclusively for a week and now I feel confident that I have reached my decision on which pair to keep. For those who are on the fence, they both are excellent phones and you will NOT regret buying either one. I think the decision should rest on what genre of music you listen to (and your budget, perhaps). Hopefully, my review will nudge you over to one side or the other. 
I am a casual listener, not as a measurebator, so don't expect frequency charts and sine waves. If they sound awesome to my ears that's all that matters to me.
Fit and Finish
PRO 900
They are built like a tank and they have lots of plastic but not the cheap and brittle kind. They look and feel like they can handle abuse without breaking a sweat. I like the PRO 900’s velour pads because the material provides a good amount of friction thus keeping the pads in place and doesn’t get hot or sweaty. The rings are pretty thick as well and provide good contact. Entire weight of the phones is supported by a small pad on top. My head hurts after about an hour of use so I had fabricated a DIY suspender (pictured) to make them more comfortable to wear for a longer period (the suspender adds more clamping force, however). Cable is just a regular stuff. Other than the fact that it screws on/off and comes with both 3.5mm and 1/4" plug, nothing exciting here.
D7000
Fit and finish on these are superb. From mahogany cups to soft leather and magnesium parts all look super smooth and classy. I am sure the materials used in these phones cost much more than PRO 900's material (excluding the driver) as there is no plastic to be found. They do feel fragile though and they look like a piece of art. The pads feel a bit anemic and don’t make a good seal around. Maybe Jmoney pads will help in this department. The pleather does feel very soft, however, and doesn’t look like it can stand the test of time. Headband is also wrapped in pleather with some minor padding. Although the padding is not thick it's fairly comfortable to wear for at least a couple of hours and more comfortable than the PRO 900's pad (larger contact patch overall). Finish on the cups are super glossy and makes me want to keep touching it
. Embedded Denon logo is also a nice touch. Cables are Y-style and pretty soft. I personally don't like this type but during use they were hardly noticeable.
Sound
Bass
My journey up the ladder of headphones was heavily based on bass. I loved M50’s bass but I thought it was a bit boomy. I chose HFI-580 over M50 because of tighter and more controlled bass although HFI-580 had slightly less amount of bass. After a while, as I got used to 580’s sound I wanted something more, more bass, more clarity, wider soundstage, and something more comfortable (580 was too tight in every way).
After reading many posts and reviews I bought a pair of PRO 900, partly because I really liked HFI-580 overall and the Ultrasone’s sound signature. PRO 900 was an immediate love at first sight and it was the bass that pulled me in. There was more than enough quality bass to satisfy my hunger. Bass on PRO 900 is definitely over-emphasized over other frequencies but that’s what makes PRO 900 so fun to listen to especially when I want to listen LOUD. PRO 900 will kick you in the gonads when you push them.
When I tried on D7000 for the first time, I felt like there was about 30% less bass compared to PRO 900. Yes, it was very noticeable. I was not impressed by the bass on D7000 but what did impress me was everything else other than bass. I decided to give them more time for my ears and brain to get used to, and to see if burn-in would change anything.
Now that I’ve listened to D7000 for a week exclusively I am thinking there’s about 20% less bass compared to PRO 900 after comparing side by side today (it's funny how the brain works). In addition, bass is more realistic on D7000. What I mean is that it sounds like real instruments playing where as PRO900’s bass sounds a bit artificial and synthesized. Perhaps this is why PRO 900 does such a good job on trance/techno/electronica. I’ve heard about D7000’s famous sub-bass and I can confirm that it is really as nice as they say. You don’t hear it often considering that it’s really low freq. but when it does you will know. Initially I was looking for (and used to) that mid/upper bass that PRO 900 is famous of but not hearing it as much made me thought there was much less bass. It turns out that there is bass but it blends in with the mid and high so it's not as pronounced as on PRO 900. Quality-wise, D7000 bass is also quite satisfying (once I got used to the sound).
Mid
When listening to instrumental pieces such piano or guitar solo, it sounds like instruments are much farther away on PRO 900 than on D7000 as if I am sitting in the back row of a concert hall whereas D7000 sounds like I am sitting somewhere in between the front and middle rows. I believe this is another way of saying PRO 900 have recessed mid (and high somewhat). Vocal is much more in-your-face sounding on D7000. I never realized how much bass was overshadowing mid and high on PRO 900 until I compared them with D7000 one after another.
D7000’s mid is the best part of these phones. It sounds so detailed and clear, I am hearing minute sounds that I couldn’t catch even with PRO 900. I heard some saying that it's still a bit recessed but coming from PRO 900, it doesn't sound like that at all. I am not sure how to describe it but it just feels so 'real' without any layers or cloudiness.
High
PRO 900’s high was quite sibilant in the beginning but after 200+ hours of use, it has rolled off noticeably. High is clean and clear but very slightly lacks details (which I didn't notice until I tried D7000). Sound can be described as to be on the cold side. D7000 was also a bit sibilant (very little to a point that it wouldn't show 95% of the time) but again, after burning in for a few day, it disappeared. D7000’s high is clean, clear AND full of details. They sound noticeably warmer than PRO 900 though. Now that the mid is more forward in D7000 than PRO 900, high doesn't sound as pronounced (more blends in with others) but quality and details are still retained as much as PRO 900 do.
Comfort, Soundstage, Sound Leak
I put a good amount of emphasis on these categories because I listen in an office environment 95% of the time.
PRO 900 are snug but they don’t clamp as hard as HFI-580. It could be slightly less, however. Velour pads are comfortable and cool. They do get a bit itchy once in a while but most of the time, I can wear them for a couple of hours without any problem, provided that I am using my DIY suspender. Without the suspender, top of my head where the pad touches gets numb and uncomfortable after about an hour.
When I took D7000 out of the box for the first time, they didn’t feel like $1K headphones. They felt lighter than they looked. When I put them on they go on light and easy, and they didn’t feel like they provide sufficient pressure to provide a good seal. Upon inspecting the pads I immediately knew why they were poor at sealing sound in/keeping noise out. Top and bottom part of the pads are pretty thin compared to PRO 900. That in addition to lower clamping pressure was the cause of poor sound isolation and leak. They are, however, very comfortable. They feel very light on your head and the leather wrapped headband also provides good and even support.
PRO 900's soundstage is not too shabby in the closed-phone standard. It's not great but better than its smaller siblings like HFI-580 or M50. D7000 soundstage feels at least twice as wide. Going from PRO 900 to D7000 it's especially noticeable, feeling quite airy.
In the sound leak department, D7000 leaks more than I hope for closed phones. Not as much open phones but easily noticeable. PRO 900 keep sound in/out better at an acceptable level but still leak a bit more than one with tighter pleather phones (580 and M50). D7000 is on the border line when using in the office. People were able to hear me listen and were able to tell what I was listening when I was listening in high volume and standing away about 3-4 ft.
Conclusion
As a whole package, D7000 sounds very natural. All frequencies play nicely to create one great harmony. No frequencies stick out like a sore thumb (if you are not a bass enthusiast, you will think it’s bass heavy but me coming from PRO 900, a bit of bass heaviness sounds natural to me). They do cost twice as much as PRO 900 and I don't think they perform 2x better than PRO 900. But I know I am approaching the right top corner in the dimishing return graph and I wasn't expecting 2x the performance. This is probably as far as I will go in that graph for now and I don't have any regret paying that amount.
PRO900 has a definite bias towards bass and they are bass lover’s headphones (so called "fun" and "colored" by some). They do this while keeping excellent high and not-bad soundstage, with comfort. For how much they cost, they are one heck of a value.
One thing to keep in mind is that PRO 900 will really shine with high quality encoding (FLAC, ALC) but punish those with lower bitrates, and this is quite noticeable especially in high freq. D7000 sound more forgiving when it comes to MP3s.
As I said in the beginning of this review, phones you will choose and love depends on your musical taste. I listen to all kinds of music and by that I mean 30% trance/electronica, 30% pop, 20% rock, 10% clasical, 10% light rock and R&B.
If I was heavily into electronic music, I would pick PRO 900 without any hesitation. One thing I know for sure is that I do miss PRO 900's incredible bass here and there while listening to D7000.
I am a so-called all-arounder, and listen to any and all kinds of music (yeah, kinda boring). In this department, D7000 handle it all oh-so nicely, while looking phenomenal.
In summary, when listening to PRO 900, they make me want to get up and start headbanging. When listening to D7000 they make me want to sing at the top of my lung. Personally I am more of a singer than a dancer 
Edited by Dougeefresh - 3/21/11 at 7:51am
