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DK-4001 - Exploded View





The biggest, most precise sound coming from the smallest package: this was always the mantra of the DK series of hybrid in-ears. Doing so meant squeezing the largest size dynamic driver possible inside the concha bowl of the ears and packing it with bandwidth-extending balanced armature drivers, all inside the tiniest available, most comfortable shell. The formula is taken to the most extreme level with the DK-4001.


Our head engineer Andy Zhao spent three years refining the acoustic formula, going through several redesigns before settling on its current form. By leveraging four of Knowles' highest performance supertweeters, and meshing it seamlessly with our highest performance Beryllium dynamic driver, the DK-4001 delivers a true flagship level experience.


After launching the DK hybrid series in 2015,

we set out to design

the most compact, optimal shell fit that would define our flagship series.


With the DK-4001 we introduced our 2nd generation shells, which were derived from a massive, diverse dataset of ear shapes that allowed us to minimize common chafing hotspots while simultaneously maximizing space available for acoustic design.


This new shape, free of any sharp inner edges and sculpted with a slight upper tilt to the insertion angle, now serves as the template for all new models in the DK series.

How do we create the most durable shells possible?

With liquid metal, of course.


This amorphous Zirconium alloy is over three times harder and more scratch-resistant than stainless steel, while simultaneously being stronger and lighter.


Incredibly difficult to make and finish, these shells tested the wits of our engineers before making it to the finish line.



Knowles' SWFK supertweeters are amongst the highest performance balanced armature units on the planet. We used two of them in tandem for four drivers in total, giving the DK-4001 the ultimate in treble headroom, and allowing its bandwidth to extend all the way beyond 40 kHz. To dial in the ideal balance between detail and harshness, we spent two months alone adjusting the tubing diameters, lengths, and damping materials, as well as the ideal crossover point for these tweeters. The result is a rich, luxuriating treble response pegged right where we want it to be.


DUNU's engineers have been developing audio transducers for over 17 years. We pooled our veteran experience into developing an ultra-precise physical vapor deposition process to deposit Beryllium layer by layer. Our exclusive dual-sided coating process enables us to create a Beryllium diaphragm that behaves essentially like one made out of pure foil-rolled Beryllium. This 13.5 mm speaker retains the speed and rigidity of a pure Beryllium cone, reproducing the kind of realistic timbre and wide staging that audio lovers crave. We allow it to sing freely by letting it take over the entire audio spectrum all the way to the low treble, reproducing music truly the way it was meant to be heard.



To take full advantage of the speed and dynamics of the Beryllium driver, we wanted to take on the challenge of integrating a bass reflex system normally found only in home speakers. After long hours and endless trials tweaking its length and size, the resultant, labyrinthine Air Control Impedance System (ACIS), was born from an obsession that nearly spiraled out of control. The end result is a spectacular bolstering of frequencies under 80 Hz while still retaining depth and agility.


A flagship earphone deserves to be mated with a high-end cable. So we scoured our sources for the highest purity OCC cabling: copper from Furukawa Electric and silver from Neotech. The only reasonable thing to do? Create a hybrid cable with strands from both sources, of course! We then upped the ante by adding in an additional interference-killing OCC copper sheath around the wires --- a construction rarely ever seen in earphone cables. The result is a hand-wound, reference-level cable worthy of true flagship status.



Exclusive to DUNU products are our patented quick-switch connectors, which allow a user to connect to all manner of portable audio interfaces, including 3.5 mm TRS unbalanced, 2.5 mm TRRS balanced, 4.4 mm TRRRS balanced/unbalanced, and 3.5 mm PRO TRRS balanced connections, with just the mere snap of a latch.



MMCX connectors have been widely adopted as one of the most popular connectors for removable earphone cables. We improved on this design further with our own patented catch-hold type connectors, lowering connection instability and pin breakages, and effectively prolonging the service life of MMCX connector interfaces. Catch-Hold® MMCX connectors are universally compatible with all standard spec MMCX seats.