Wow is the first word that popped into my mind after putting on these IEMs.  Dunu has outdone themselves again.
 
SOUND
These are quite possibly the best IEMs I have ever listened to.  These tiny triple drivers have made me consider selling my Sennheiser HD600s on multiple occasions.  The soundstage is far better than the average IEM soundstage, which is definitely helped by the 10mm dynamic driver.

Bass:  Bass is so clean, clear, and detailed.  It may be a tad bass heavy for some, but nothing a bit of EQ can not fix.  They execute every bass line I’ve tried on them beautifully and truly remind me of the bass on the HD600s.  But what else is new, Dunu’s headphones all have amazing bass capabilities.

Treble:  Out of the box, the treble was way to harsh for me, making it a bit painful to listen too.  After messing with my EQ settings, everything was perfectly balanced.  After breaking them in a bit, the treble became less harsh, and now sounds perfect.  As these are triple driver IEMs, the 10mm dynamic driver is pumping out bass, while 2 balance armatures pump out the mid and highs.  As a result, you can truly hear things in your music that you have never heard before.  The treble is clean and astonishingly excellent.  It handles soaring violin lines and high hats perfectly now that they are broken in.

ACCESSORIES
Dunu did not hold back on packing their nice packaging full of earbuds and filters.  There are 9 different pairs of silicon tips, and 3 different medium sized Comply Memory Foam tips in the Isolation, Isolation Pro, and Comfort style.  The travel carrying case is absolutely gorgeous, and completely protects the headphones.  Also comes with an airline adapter, 3.5 to 6.5 jack converter, and a myriad of different sound filters to modify the sound signature.  These also come with a bunch of different “slide on” accessories to securing the headphones in the ear.

ISOLATION
When the Comply Memory Foam tips are on them, and music is playing, these have the best isolation I have ever heard.  I would compare the isolation level to my Bose QC20is (which have ANC, the best ANC I have ever heard).

COMFORT
This is the only section that I have a problem with.  These are not very comfortable for long use.  Because of the “slide on” accessories (which are necessary to provide the high level of isolation), the 2000Js can be uncomfortable to wear for long periods of time.  Most of the time however, it is uncomfortable at first, and then I just forget they are on.  When I take them off, some of the inner folds of my ear are sore, but this soreness can be quickly massaged away.
 
MY RECOMMENDATIONS TO DUNU
As I have said, the only problem I have with these IEMs are the comfort and fit.  The Titan 5’s perfectly fit in the ear canal, so I’d love to see this headphone updated in the future with a better body that would make them more comfortable.  Honestly, thats the only complaint I have.  I would not change anything else (except maybe adding a removable cable).  Great job.
 
SUMMARY
These IEMs are incredibly impressive.  Their sound quality is worth way more than the $215 I paid for them.  Great for all types of music, really inexpensive for what they are, I’d recommend any headphone lover to grab a pair of these.  In the future, I might actually pop these on to jam out over my HD600s, but who knows.  Im excited to see what else Dunu will come out with.

A very big thanks to DUNU for the DN-2000J review sample! I've been a great fan of DUNU hybrid IEMs since I bought DN-1000 and DN-2000, and reviewed them some time ago. It took me almost a year to complete this review due to unforeseen high workload.
 
http://www.dunu-topsound.com/DN-2000J.html
 

 
 
DN-2000J is a hybrid IEM, in the same family as DN-1000 and DN-2000. It has one dynamic driver and two BA drivers per channel. One special note, the dynamic driver seems to be quite special, the diaphragm is made of liquid crystal composite with Titanium coating, and it performs remarkably well in DN-2000J.
Having similar model number and housing design as the DN-2000, one common question is whether the DN-2000J is an improved version of DN-2000. In my opinion, yes, an improvement, but not a replacement. DN-2000J does improve certain design features of DN-2000, such as the knurled nozzle to hold the eartips tighter, slightly thicker cable that feels stronger and more durable, and improved detail and transparency in the sound quality department. But DN-2000J in my opinion doesn't replace DN-2000 due to the rather different tonality. With more treble emphasize than DN-2000, DN-2000J is generally brighter than DN-2000. And might be a little too bright for some people. DN-2000 tonality to my ears sounds very linear, very good balance from bass to treble. Probably a little lacking on the upper treble coverage, but to my ears, DN-2000 is one rare IEM with very linear tonality, especially on the bass to upper mid region. DN-2000J tonality might not sound as 'pleasing' as DN-2000 and has shifted more towards analytical sonic character. For those who like the DN-2000 tonality (like me), the analytical nature of DN-2000J might not be considered as an improvement over DN-2000, and might prefer the DN-2000 tonality instead. But for those who prefer a more transparent sonic signature, DN-2000J superb transparency and clarity are certainly a very welcome improvement.
 

 
 
 

Summary:

 

1. An excellent monitoring IEM with good accuracy, superb transparency, clarity, dynamic, and detail retrieval capability.
2. Neutral-analytical sound signature and highly revealing. Definitely not for those looking for smooth-warm sound signature, and probably not for vocal lovers as well. DN-2000 is the better option for those looking for a more pleasing smooth-warm signature while still having pretty good transparency.
3. To get the best sonic character to match individual preference, testing all the sound tuning options like eartips, bass ring, and DNK rings, is a must.
4. Bass ring is recommended to bring the bass level to a more realistic level (~6 dB boost).
5. Excellent bass quality, reach very low, fast, detailed, and very rich in texture. Probably the best bass quality in this price category.
6. With bass ring, the tonality is mildly V shape with more emphasize on the treble.
7. Best paired with neutral to warm sounding amplifiers or players.
8. Might not be the best choice for Pop recordings, but definitely one of the best IEM for classical, binaural, and other distant miking recordings, as well as Pro Audio applications.
9. An improvement, but not a replacement of DN-2000.

 
 
 

Pros:

1. Technically excellent IEM, very revealing with excellent level of detail retrieval and transparency.
2. Excellent coherency between all the 3 drivers.
3. Excellent 3D holographic imaging.
4. Superb bass quality.
5. Sound tuning option with bass ring, DNK rings, and various eartips.
6. Easy to drive and not much affected to different value of amplifier output impedance from 0 to 10 ohms.
7. Generous accessories.

 

Cons:

1. Tonality probably a little bright for those who prefer warm sonic character.
2. Though the knurled nozzle has better grip for the silicone eartips as compared to the smooth nozzle of DN-2000, but still need to be improved further, as occasionally eartip still left stuck in ear canal when unplug the IEM.

 

Suggestions for Improvements:

1. Eartips fitting, especially the Silicone eartips.
2. Detachable cable.

 

 
 
 
 
From my observation, though there are many various personal preferences on sound signature and tonality, I observed that there are 2 major groups of user, the 'Sounds good' and the 'Sounds right'. The first group, the 'Sounds good', are those looking for a more pleasing sound signature. It doesn't really matter if the sonic character is a little coloured, not very detailed, or less accurate, as long as overall sonic character sounds good and pleasing, matches to their personal preferences. The second group, the 'Sounds right', prefer detailed, transparent, and accurate sonic character that reasonably close to life performance, even though the sonic character might be unforgiving for less than stellar recordings. If the older DN-2000 probably sits in between the 'Sounds good' and the 'Sounds right', DUNU DN-2000J is clearly more suitable for the later.
 
100% early responses that I got from friends when I asked them about DN-2000J, are quite similar. They all said it is quite bright sounding. Some said that the tonality is simply too bright to their liking. Unfortunately that's quite true when I tried it out of the box, not a very positive first impression. But, thanks to DUNU, they provide bass ring adjustment that will cover the front bass port of DN-2000J when used, and will increase the bass response of DN-2000J by around 6 dB (about twice). Personally I prefer to use the bass ring for a more linear, more balance and less bright tonality. A few friends tried again with bass ring and the feedback was more positive. I think if DUNU put the bass ring as the standard setup from factory, general perception of DN-2000J will be different. Many friends that tried DN-2000J at local shops, never tried it with the bass ring. Once it sounded too bright to them, they simply lost interest of DN-2000J and don't bother to try the tonal adjustment that provided as standard accessories by DUNU. My suggestion to DUNU, probably it is better to put the bass ring as default setup from the factory, for the reason that people are generally have more tolerance to higher level of bass than higher level of treble. It is a pity if some people might avoid DN-2000J due to the rather hot treble at first impression. First impression is very important, therefore in my opinion, to put the bass ring as default factory setup is a better marketing approach.
 

The left earphone showing nozzle with Bass Ring and DNK Ring. On the right, the very small bass port shown at the base part of the nozzle.
 
 
DN-2000J transparency and the level of perceived detail are in the category of high-end IEM, and have been improved from DN-2000. What amazed me most is the coherency between drivers and the level of detail and texture across the audio spectrum, from sub bass to upper treble. Something I consider rare for multi driver IEM. Starting from DN-1000 where I can notice a slight different sonic signature between the lower frequency region served by the dynamic driver and the upper frequency region served by the BA drivers, DUNU has kept improving the coherency between the drivers in their IEMs. DN-2000 drivers coherency is better than DN-1000, and I'm glad to say that DN-2000J drivers coherency is probably one of the best I've ever heard. It is quite seamless across the frequency spectrum. The sonic signature between the bass region and the upper frequency region is very coherent. The Titanium coated dynamic driver truly delivers high quality bass. Bass is fast, tight, reaches low, and beautifully textured. And the sonic character of the dynamic driver matches nicely the sonic character of the BA drivers.
 
Tonality is tunable to some degree. Out of the box with the stock grey eartips, without bass and DNK rings, DN-2000J sounds smooth bright. Treble is moderately emphasize, and generally a little too bright for modern genres, but good for classical and audiophile recordings, especially those stereo recordings that recorded with distant miking stereo technique. Most obvious tuning is the bass ring that close the bass port near the nozzle, and boost the bass around 6 dB. But please take note, the bass ring will cause some mild driver flex. Without bass ring there is no driver flex. DNK rings adjusts the treble part in a subtle way. And eartips also affect the tonality to some degree. To try the combination of all of them is highly recommended to get the best sonic character that suit individual preference. My best recipe for DN-2000J is: Bass ring + the stock DUNU translucent grey silicone eartips, medium + red DNK ring.
 

 
 
Though probably the treble takes the most attention at first, but DN-2000J bass is actually what I consider the best performance of DN-2000J. It is surely one of the best IEM in the bass department. I'm not talking of bass quantity here, but bass quality. Quantity wise, without bass ring, to me it is on the low side, a bit too low to what I consider as realistic bass level, but not yet anaemic. With bass ring, the bass level is just nice for my preference. The bass reaches very low to sub bass, super tight, fast, very detailed, and very rich in texture. Using bass ring, the bass has good body and punch as well. Simply 5 stars bass quality!
 
DN-2000J grew on me. From 'Uurgh the treble is bright!' to 'Wow! This is really a very capable and accurate IEM!'. Honestly, after using it for a few months, I really like DN-2000J, and admire its capability. It is one of the most transparent and accurate IEM I've ever tried. It has the level of transparency, detail, and texture way better than many other IEMs in this category, and not only in this price category, but also competing well with some higher priced IEMs I've tried. But please take note, DN-2000J might not suitable as a 'general all-rounder' IEM. It is very revealing with some emphasize on the treble, so recording flaws on less than stellar recordings will be revealed bluntly. Though DN-2000J is not really my favourite IEM for Pop music, but it is really an amazing IEM for classical, binaural, and audiophile recordings that recorded with aim to achieve natural tonality and stereo imaging. Some of my audiophile albums with distant miking recording technique sound best on DN-2000J. For example, audiophile albums like the '8 Ensembles in 1 Bit', many of Chesky recordings and the famous Chesky binaural album, 'Dr. Chesky's Sensational, Fantastic, and Simply Amazing Binaural Sound Show', so far DN-2000J has been my IEM of choice for those recordings. Those albums sound more realistic and lively on DN-2000J as compared to my other IEMs.
 

 
 
I have both Sennheiser HD800 and Beyerdynamic T1 that beside for music listening, I also use them occasionally for recording and mixing due to their analytical character. Somehow DN-2000J sonic character reminds me of those two flagships headphones, and in my opinion DN-2000J has enough transparency and accuracy to be used for recording and mixing as well. Therefore I called DN-2000J, 'DUNU Reference Monitor'.
 
 
 
 

Build Quality

As mentioned earlier, after having it for about 1 year, my only complaint is the Silicone eartip fitting to the nozzle that is not tight enough and sometime the eartip left stuck in my ear canal when unplugging the IEM. Besides that the build quality is pretty good, and it has been proven to be quite durable so far, though I won't recommend using it for exercise.
 

Some scratches on the metal housing after about 1 year of use.
 
 
 
 

Gear Pairings

DN-2000J is easy to drive, and at the same time can take some high output and get very loud without getting easily distorted. I got wonderful pairings with many of my gears such as Onkyo DP-X1, Chord Mojo, the old Centrance DACport with 10 ohms output impedance, as well as the newer Centrance DACport Slim, and some other gears. It also pairs wonderfully with my AT-HA22TUBE tube amp. The analytic sounding ifi micro iDSD headphone output is in my opinion not a very good option for DN-2000J. Fiio X3 2nd generation that pairs wonderfully with DN-2000 unfortunately doesn't pair well with DN-2000J either. Rule of thumb for DN-2000J, avoid analytical sounding amp or player, and pair it with neutral to smooth warm sounding gears and it will sing.
 

 
 
Driven by first generation of AK100 with 20 ohms output impedance, DN-2000J still sounds reasonable natural. Bass level drop with higher impedance, so overall tonality gets a little brighter on AK100, compared to other player with low (less than 1 ohm) output impedance. Bass level probably drop around 3 dB on AK100, quite noticeable, but overall tonality still quite natural. I prefer the bass level with low output impedance player. Based on experience, the safe range of amplifier output impedance for DN-2000J is I would say 0 - 10 ohms.
 

 
 
 

Comparisons

 
 
DN-1000, DN-2000, and DN-2000J offer some sound tuning using different eartips and DNK rings. The setup that sound best for me are:
DUNU DN-1000: JVC EP-FX8M-B, medium eartips.
DUNU DN-2000: The stock DUNU translucent grey silicone eartips (2K Tips), medium + silver DNK ring.
DUNU DN-2000J:  Bass ring + the stock DUNU translucent grey silicone eartips, medium + red DNK ring.
 
More coverage of DN-1000 and DN-2000 can be read here:
http://www.head-fi.org/t/727286/review-and-comparison-of-dunu-dn-1000-dn-2000-jvc-ha-fx850
 
 
 

DN-1000

Though I really like the fun and lively sounding of DN-1000 especially using the JVC EP-FX8M-B eartips, I have to admit that DN-2000J is clearly superior to DN-1000, especially in coherency and transparency department. Coherency, detail, and transparency are clearly better on DN-2000J and worth the price different between them. DN-2000J bass is much better, faster with better detail and texture. DN-2000J also has better upper treble extension that makes it sounds more transparent with better 3D imaging as compared to DN-1000. Using the JVC eartips DN-1000 treble does sound slightly smoother and more ear friendly than DN-2000J, but the wider and more holographic imaging of DN-2000J gives a different, more realistic listening experience. Value wise, they are 5 stars in their own price category.
 
 
 

DN-2000

DN-2000 will still be my reference for linear tonality, as tonality wise it sounds a little more linear than DN-2000J. But on the other aspects like coherency, dynamic, clarity and detail retrieval, DN-2000J is clearly better than DN-2000. DN-2000J has better upper treble extension, sounds brighter and more transparent than DN-2000. Bass detail and texture also have been improved on DN-2000J. While DN-2000 sounds smoother with a little touch of warmness, with softer and a more ear friendly treble. I really like them both almost equally. When I'm travelling light with Fiio X3ii, DN-2000 goes with me. When I need a more detailed and transparent IEM during recordings or to audition and testing gears, DN-2000J is my IEM of choice. When I'm listening to Pop and vocal, DN-2000 sounds friendlier to my ears, while for classical DN-2000J breaths more air with better holographic imaging.
 

 
 
 

1964 Ears V3

Besides DN-2000, 1964 Ears V3 is another reference IEM of mine that to my ears sounds 'balanced'. Kind of another variant of DN-2000 with better bass and dynamic, and sounds livelier than DN-2000. V3 is less analytical and less bright than DN-2000J, and closer to DN-2000 tonality. V3 has very good detail retrieval without sounding analytical. Transparency wise, DN-2000J is better than V3, so some recordings that benefit from transparent sound signature like the few albums mentioned earlier, sound more realistic and more holographic on DN-2000J. While the fuller, beefier, and slightly warmer signature of V3 sounds nicer on vocal and pop recordings. When looking for transparency and high detail retrieval capability for pro audio monitoring, or listening to classical I tend to pick DN-2000J. While when I want to enjoy vocal and some other closed miking recordings, V3 or DN-2000 are usually my preferred IEMs. On volume setting, V3 is more sensitive than both DN-2000 and DN-2000J, and requires less volume to get similar loudness. And as expected from the less bright tonality and higher sensitivity, V3 is easier to match with almost any gears that I have. It adapts very well from analytical sounding players or amps to the warmer sounding ones. While DN-2000J doesn't go very well with analytical sounding players or amps. So while DN-2000J excels in transparency and holographic imaging, but it is more polarized towards certain type of recordings mentioned earlier, and Pro Audio monitoring applications. While 1964 Ears V3 is in my opinion a better all-rounder for music listening, especially for modern genres with closed miking recordings.
 

 
 
 
 

Measurements

I don't have standard IEM measurement equipment, and I found IEM frequency measurement to be rather complicated. I use USB measurement microphone, MiniDSP UMIK-1 and a DIY acoustic coupler that I made from heat shrink tubing. 
 

 

 
 
So far from some testing I’ve done, I observed the following:
1. The length and volume of the acoustic coupler affects the upper treble response. Longer acoustic coupler will create unnecessary treble peaks above 10 kHz.
2. Room temperature affects the bass response. Similar measurement done in 25 degree Celsius and 31 degree Celsius room temperature consistently showing around 6 dB differences in bass response. Bass response is higher in lower room temperature.
3. Level of loudness during measurement affects the smoothness of the overall frequency response. Generally measurement done in louder volume showing smoother frequency response.
4. The equipment that I use doesn't seem to be accurate for the upper treble region, therefore only useful for up to around 9 kHz. Measurement result from 9 kHz onward can be ignored.
 
I suggest to always read IEM frequency response measurement result in the context of the measurement environment, as they are mostly useful only as comparison to other IEMs that are measured in the same measurement environment using the same equipment. So please take note that all the frequency response measurement shown here is not a standard measurement, therefore cannot be used for comparison with other measurement. This measurement is only to show comparison of estimated frequency response of the IEMs that were measured in the same environment using the same equipment.
 
The following measurement for DN-2000J was done in an air conditioned room, at around 24 degree Celsius room temperature. I used the short DIY acoustic coupler that gives around 4-5 mm distant between the tip of the silicone eartip to the microphone. The program I use for measurement is the famous Room EQ Wizard, REW v5.14. I measured left channel and right channel multiple times, take 3 most consistent measurements for each channel, apply Psychoacoustic smoothing, and then average the result.
 
 
The following is the frequency response measurement for the Left and Right channel, without and with Bass ring. Both Left and Right channels have pretty good consistency, and there is no audible difference between the Left and Right channel.
 

 

 
 
The following is comparison of DN-2000J frequency response (average FR from Left and Right channels measurements) with DN-2000. We can see higher treble response that explains the brighter tonality of DN-2000J.
 

DN-2000J without Bass ring (Yellow), in comparison to DN-2000 (Orange).
 
 

DN-2000J with Bass ring (Blue), in comparison to DN-2000 (Orange).
 

Measurement at 60 Hz shown that the Bass ring boost the bass area by around 6 dB.
 

DN-2000J bass response comparison, with (Blue) and without bass ring (Yellow)
 
 
 
DN-2000J to me is a keeper. It is probably not an IEM that impressed me at first try, but it does grow on me, and the more I use it the more I impress by its capability. Now it is my favourite IEM for listening to classical, instrumental, and binaural recordings. It is also the IEM that goes with me for Pro Audio activities. Kudos to DUNU!
 
 
 

Specifications:
Drivers: Dynamic (10mm) + 2x Balanced Armature
Frequency range: 4 Hz-40 KHz
Impedance: 8O
Sensitivity: 112±2dB
Connections: 3.5mm Gold-plated
Cable: 1.2m
Weight: 21.8g
 

 

 
 
I apologize for the incomplete Silicone eartips shown in the picture below. Somehow I misplaced the Silicone eartips and I couldn’t find them during picture taking. Please check accessories picture from other reviews for all the Silicone eartips that come with DN-2000J.

 

 
 
 

Earphones / IEMs:
DUNU DN-1000
DUNU DN-2000
DUNU DN-2000J
1965 Ears V3
 
DAPs, DACs, & Headphone Amplifiers:
Astell&Kern AK100
Audio-Technica AT-HA22TUBE
Chord Mojo
Fiio X3 2nd gen
iBasso DX90
ifi micro iDSD (firmware 4.06)
Onkyo DP-X1
Superlux HA3D
 
Measurement Microphone:
MiniDSP UMIK-1
 
Some recordings used in this review: