Dunu Vulkan ($379): What’s in a name?
Upon reentering the portable market in earnest, the Dunu Titan 1 was my first purchase. For the price, it sounded quite good. Then Dunu seemed to fall a bit behind other far eastern manufacturers, or so it seemed. With the SA-6, Dunu reentered with vigor. Multiple changeable jacks were included, so all one needed to do was change the jack, not the whole cable. It worked, and we consider the SA-6 as one of the top contenders at the $500 IEM price. It also seemed that Dunu took a step away from the traditional far east sound of a nice bright signature, which carried over into plenty of air between notes. While not a bad signature, it really was not for everyone. That type of signature works wonders for classical or opera music in our opinion, but not so well with other genres.
Celebrating their 20th anniversary soon, Dunu started this road with the models mentioned earlier. Moving upscale, the DN-1000 coaxial hybrid IEM of roughly 10 years ago claimed to be the first hybrid IEM under $1000. While we mentioned that it seemed they had taken a step back and were not heard from for some time, they were working diligently on introducing their new technology into a budget-friendly price. The Vulkan is the latest evolution of their coaxial designs, using their expertise in design and tuning. Priced just under $400, it sits in the middle of their range, between Falcon Pro and EST112 (part of this information was taken from the follow excellent review: https://www.ear-fidelity.com/dunu-vulkan/)
The Vulkan follows this “new” Dunu sound/research with much going for it, including the changeable jack. With gorgeous looks, excellent build and the jacks going for it, there is much to like. Read on for more positive vibes.
MODEL: DK-X6 (VULKAN)
NET WEIGHT: 17 g
FREQUENCY RESPONSE: 5 Hz – 40 kHz
IMPEDANCE: 15 Ω at 1 kHz
SENSITIVITY: 109 ± 1 dB at 1 kHz
TOTAL HARMONIC DISTORTION: < 0.3% at 1 kHz
DYNAMIC DRIVER UNITS :
8 mm Cross-Linked Polyethylene Structural Foam Cell Dome
with Soft Independent Surround 
8 mm Nanocrystalline Titanium-Coated Diaphragm 
BALANCED ARMATURE UNITS :
Knowles Mid-High Driver (×2) 
Knowles Dual Supertweeter (×1) 
WIRE MATERIAL: 4 Core, High-Purity, Silver-Plated OCC Copper Type 1 Litz (DUW-02S)
LENGTH: 1.2 ± 0.1 m
CABLE CONNECTOR: Patented Catch-Hold MMCX Connector
PLUG CONNECTOR: Patented Q-Lock PLUS Quick-Switch Modular Plug System
INCLUDED PLUG TERMINATIONS:
3.5 mm TRS Single-Ended
2.5 mm TRRS Balanced
4.4 mm TRRRS Balanced
Astell & Kern ACRO CA1000
Packaging has always been a strong point for Dunu models, and when one spends this kind of money, the presentation melds well at this price. Much useful information is also printed on the box from specifications, to driver type and size; as well as information regarding the cable and accessories included. The cable itself is called the DUW-02S, with the Q-LOCK PLUS system for changing jacks. It’s a four-core, silver-plated OCC copper of type 1 Litz design. MMCX connectivity is used for additional support. The cable lays nicely and is of a softer variety, aiding in no microphonics.
The faceplates are inspired by the Japanese art of Mokume Gane, a 17th-century technology producing complex metal laminates in separate layers. The name translates to “wood grain steel”. This laminate was then used to produce swords and knives like katana, wakizashi, and tanto. You can somewhat feel the separate “layers” on the dark gray/black faceplate and under the right light, is stunning in presentation. A slot on the forward side acts as a vent, completing the look.
The same dark gray/black carries over into the moderately sized shells complete with “Vulkan” and either “L” or “R” on the inside. Thankfully, no fancy ear nubs are found on the inside, affording good insertion depth, even with the wider than “normal” nozzle. A silver screen covers the large nozzle as well. With a shrink wrap sleeve over the business end of the cable, there is a good over ear guide, leading to the understated stunning shell.
The Q-Lock Plus changeable jack system allows the user to utilize three jacks on one cable, alleviating the need for multiple cables. The wizardry inside switches to balanced or single-ended depending upon the connection, whether it be 3.5mm for single ended (TRS), or 2.5 (TRRS) & 4.4 (TRRRS) in balanced mode. One might worry about the complexity or failure rate, but you should not. Built to withstand several hundred to thousands of changes, the jacks hold up very well.
The Vulkan utilizes six drivers per shell: four Knowles balanced armatures (2 mid-high & 2 super tweeter) along with one 8 mm Cross-Linked Polyethylene Structural Foam Cell Dome
with Soft Independent Surround and one 8 mm Nanocrystalline Titanium-Coated Diaphragm (a co-ax dual dynamic driver). That vent slot (Air Control Impedance System, ACIS) on the faceplate helps alleviate pressure build up, as well as control the bass segments; giving more control over the lower end. Dunu does their testing inhouse, along with design and build so they can control all points except for the actual building of the drivers. This helps to control sound quality from build point to finished product as well.
The SA-6 is one of our favorite IEM’s at the $500 price point. Many will be satiated with it to the point of stopping their search. The Vulkan may have the same effect, but at a lower price. With excellent upper reach control, and the dual dynamic drivers caring for the lower, the Vulkan proves its mettle across the sound spectrum.
The bass while not as impactful as some other dual dynamic drivers still holds its place with excellent control of the lower spectrum. Taut and controlled, I do wish for a little longer decay so those tendencies would linger. To me this would give more girth to the bass while not meddling too much into the mids. Nonetheless, the bass can show itself nicely such as on Taylor Swift’s new song Snow On The Beach. From her absolutely highly acclaimed Midnights album, the song enters with a solid bass line, and there is a bit of reverb through the Vulkan. The same holds true on You’re On Your Own, Kid, which makes me believe it is on purpose. Giving excellent tight control here makes that reverb all the more refreshing. Tip choice is paramount to good quality bass, and the Vulkan benefitted from one of my trusty Comply foam tips. Bass became very, very good as a result.
One need not say much about Swift’s vocals. They are divine. And through the Vulkan, there is a certain sumptuousness to it, which makes the musical notes completely believable. Often with multiple balanced armature drivers, there is a tendency to “overproduce” the upper mids leading into the high notes. Thankfully here, there is a certain trueness to her vocals, with no underlying analytical sounds either from the extremes of her vocals or the background instruments. With more drivers, you can run into a “business” of sound, which translates into that analytical sound of which I speak. Not here as her steamy voice comes through with complete realism.
Moving into the upper regions, cymbal clashes, even those made by digital representatives sound realistic as well. There is excellent reach of note, giving very good air to the notes, but not translating to a thinness often accompanied by extension in the treble region. This translates into good weight to the notes across the spectrum as well. Often when treble sounds brittle, or glitzy, it dissuades from the overall signature, making it seem thinner or more brittle. Not here though. The treble gives extension where needed, and spreads the notes out in an even manner, complimenting the taut and controlled bass. The benefit of this? The mids. Female vocals are made for the Vulkan. Trust me.
While the parts listed above give an excellent sound signature, I did find that the reach from the top makes for a bit tedious sound on some songs. Especially those with a preponderance of upper, such as EDM. Sound stage is still excellent in the three dimensions, giving very good placement to the instruments and layering. Height to me dominates the 3D cube, but not to the detriment of width or depth. In fact, that expansion may give a false sense of expansion, with the depth showing through with excellent character on certain songs. Width is beyond my ears, making its resolve to give that 3D shape good shape.
We are fans of Dunu, counting some of their models as the best or near best in their respective price categories. We wholeheartedly recommend the SA-6 to many who have that money to spend, because with each jack change; you can tailor the signature a bit to fit your music. Dunu in its 20 years has taken that experience of “tinkering” to settle on a fairly unique structure with the changeable jacks, as well as providing an excellent sound foundation to back it up. While not perfect, the Vulkan shows it can certainly fit into the market as Dunu’s low-cost hybrid IEM. We hope that Dunu keeps innovating, going their own way to produce what they think is the best that they can provide. If the models mentioned here are the result, Dunu has followed their heritage line of hybrid driver IEM’s with exemplary fashion. We can highly recommend a listen if you are looking for a fun, engaging sound signature in your next IEM.