I wrote this to put on djforums.com as a user review (I was just bored really), and I thought that maybe there's some hopeless soul out there that wouldn't find it from there and that there'd be no harm in posting it here as well (it's basically zero extra effort anyways). So here's the review, in all its' copy & paste glory.
If you want pictures or videos there are plenty of them online, so here's a stock photo.
http://www.pioneerelectronics.com/St...Down_Large.jpg
I'll only review headphone/IEMs I have at hand starting off with the Pioneer HDJ-2000, Shure SE535 and maybe lying around somewhere as a pair of spares, the AKG K518 LE (which only differs from the DJ version cosmetically and shorter cable).
The HDJ-2000s are as a pair of DJ headphones highly regarded by a larger part of the community with a lot of
solid points, but with some flaws often overlooked.
Manufacturer product sheet: http://www.pioneerdjusa.com/images/gear/pdf/HDJ2000.pdf
Sound: 4/5
The HDJ-2000s have a warm and very forward, yet clear mid range and solid bass with a good punch. Not only is the mid range accentuated, the bass from around 50 Hz and up is also enhanced, and this extends up to around 500 Hz, probably up to +5 dB SPL around 100Hz measured against the SPL at 1 kHz, which is highly noticeable. And while the bass is solid, it doesn't extend very to the lower frequencies, as the HDJ-2000s have a very steep bass rolloff. I suspect that from the 100 Hz mark down to the lower end of human hearing, the rolloff results in roughly a -20 dB drop, yes - it's a massive bass drop (pun somewhat intended, I'm sorry).
Furthermore, when Pioneer states the HDJ-2000s go down to 5 Hz, considering the bass rolloff, they clearly mean that it's possible to shoot a 5 Hz sine wave through them. While 5 Hz cannot be heard, it can definitely be felt. However, you will need a very hot signal for that, and it is not controlled at all - weird hissing mechanical noises can be heard. This has not been a limitation from any audio interface, I tried this with professional grade signal generators (which for the record was visually checked with an oscilloscope of similar quality) which I had at hand from my university. Conclusion: the deep bass is lacking due to a steep rolloff, and they definitely do not produce 5 Hz in an intended manner. I have no similar experience for the 30 kHz mark, I must have forgotten to look at it, or maybe I ran out of time.
The largest disappointment for leisure listening is the upper high range though. A lot of clarity disappears here, sounds becomes harsh and grainy at best. The upper high range is likely the largest flaw with the HDJ-2000's audio quality, it's what turned me away from them to look for alternatives, it's one of those things that once you hear and realize what's lacking you can't ignore it.
Another thing like that is the channel imbalance present in the HDJ-2000s, the left channel is slightly louder when run in stereo. Most people may actually never hear it, and just assume it's either one's own hearing or psyche (or a combination of both). This has been reported by several individuals on different forums, but I've yet to find any hard figures on how large the imbalance is.
The mono mode on the HDJ-2000s is probably the best passive mono summation switch I've heard in a pair of headphones ever. That being said, it does degrade sound quality, but hey - it's a mono switch for single ear monitoring (or whatever other reason one might need for leisure or professional listening), and there are much worse on-headphone mono summers.
This might sound a bit hard on the HDJ-2000's sound quality, and to be fair they are not audiophile headphones, but they're good sounding, warm and enjoyable save for the deepest bass (there are mods to enhance the deep bass) and the somewhat harsh upper high range. I still listen to them from time to time and use them when mixing at home, and I would recommend them for DJs in terms of audio quality, but they are sonically overrated on DJ forums. They are easily driven, and can handle a very strong signal. They don't sound muffled like a lot of cheaper headphones, but I definitely feel a an auditory' veil' between me and the music, some things just won't get through. That said, they're still a solid 4 out of 5 for DJs in the sound department.
Sound Isolation: 4/5
Isolation is another point where these headphones are good (better than the average on ear headphone), but even better isolation can be achieved, such as with Sennheiser's HD25s (which unlike the Pioneers are on ear, not over ear, a difference important noting). However, well fitting IEMs will isolate much better. Oh, and the HDJ-2000s leak quite a lot of sound, not that it's a problem on scene really.
Durability: 3/5
Wow, this will be a fun one. I've had my Pioneers repaired once since they broke in the plastic parts above the hinge. Yes the magnesium alloy is nice, it's never failed me, but the plastic has. After the repair, the cable started going bad (something I to be expected over time), an easy fix as it's detachable and replaceable. But after a few months, plastic cracks were starting to reappear on the new headband. This is also a very common problem with the HDJ-2000s, and possibly the biggest. Pioneer should have opted for a metal band surrounded by soft rubber instead of lots of plastic parts. Less is more, Pioneer. Less parts used, lower complexity, fewer repairs, more profit for you. Now there's a carrying case designed for them one can purchase, but it's too little, too late for this DJ.
Comfort: 5/5
In terms of comfort, I have yet to find any headphones that are more comfortable than the HDJ-2000s. I can literally wear this for every waking hour without any fatigue. They are super comfortable, highly adjustable, they don't get (sweaty) warm, they aren't super light - but the weight they have provides a solid feel. If there would be something to point out is that the cable can be a bit heavy and bulky, but to be perfectly honest, it's not a problem in the booth. It's more a problem if you use them as portable headphones and bring them with you. A 3m, heavy coiled cable with a bulky connector playing from your phone/PMP is a hassle at times. However, the cable is user replaceable, and there are plenty of shorter and lighter cables available (or one can easily make one).
Size: 4/5
The HDJ-2000s are over ear headphones, with a headband with room to grow, well cushioned, fluffy pads and a large cable - they're bound to be large. However, they are easily foldable and become very compact. Also, they are not bulky when you're wearing them, they actually feel slim.
Overall value: 4/5
Would I buy this again if it broke? There was a time when I'd say yes in a heartbeat, right now, as I've moved over to mixing with IEMs, it would more likely be no. Would I recommend them for a dj looking for a pair of over ear headphones? I would tell them about my own experience with them and their limitations. I realize it may seem I'm trying to bash on the HDJ-2000s as much as I can, but I'm not - they have a lot of ups, and they also have some (often ignored) downs. They are expensive, and right now if I would have to buy a pair of headphones (not IEMs) for DJing, I would probably investigate the Sennheiser HD25s a bit closer. Probably a backlash from the durability problems (the HD25s are more easily repaired by the user), but the few times I've listened to them they've been enjoyable. As stated earlier though, the Sennheisers are on ear, and not over ear, so it's a different beast altogether. (And this is not a permanent recommendation, just my own thoughts, subject to change, as of April 2012).
