DUNU LUNA | Pure Beryllium Rolled Foil Diaphragm IEMs
The DUNU Luna is a small work of modern art, and it comes packaged with a bevy of useful accessories put together in a luxurious and eye-catching fashion. Of course, the Luna is more than a pair of pretty earphones with some cool swag. It has a vibrancy and energy that comes from detailed mids and highs, and a natural lifelike tuning. Read our full review.
LUNA is the world's first pure beryllium rolled foil diaphragm flagship dynamic in-ear. As our flagship product, LUNA was tuned to a reference sound signature --- deep and natural imaging, even and smooth from top to bottom, and maximized for extension at both ends. The result is the most supremely detailed, transparent, sumptuous sounding earpiece ever crafted by DUNU. It is our best representative of beryllium’s full sonic potential, and we are absolutely thrilled to have everyone experience LUNA.
We partnered with Hangzhou-based designer and long-time audiophile Moses Xu and his team at Zinc Studio & Audio Salon for the industrial design.
LUNA is a story within itself, reflecting the spirit of the first moon landing 50 years ago, and elevating the manner in which in-ear monitors are perceived.
「玥」is the representative Chinese character for the LUNA, signifies a heavenly, pearlescent gift from the gods. From this luminous, round canvas, Xu worked to elevate every design element for the LUNA, blending them seamlessly with an overarching moon landing theme.
LUNA’s circular, concave faceplate serves as a physical representation for the changing albedo of the moon across each moon phase, while the asymmetric lip delineates waxing and waning crescentic shapes.
The outer facet of LUNA’s CNC body of custom-formed titanium alloy is sandblasted to reflect subtle specular highlights, just as the craterous central concavity draws in a penumbra of shadow.
The inner facet of the body preserves distinct lines created by the machining process, creating natural contour lines much like a topographic map. Functionally, the concave recess and slanted lip allow LUNA to be inserted and removed comfortably.
Man & Moon
Whereas the body of the LUNA is contoured, the beveled edges of the cable connector interface represent a more technical facet to the moon theme --- an abstract representation of the Apollo spacecraft.
Transitioning from man-made starkness to celestial fluidity, the smooth, domed end cap serves as a point of transition from human engineering to planetary body.
From the side, with cables attached, one can make out the profile of an orbital path taken to the moon. Finally, when turned on its side, custom-made blue silicone tips serve as a reminder of Earth as seen from the Moon.
LUNA's housings are precision machined entirely from a custom-modified grade 5 titanium alloy.
Known for its structural integrity, grade 5 titanium alloy, also known as Ti-6Al-4V and TC4, is notable for its prevalent, workhorse-type use in aerospace and other industries where the strength of titanium is its highly important.
But we reformulated this alloy with a custom-modified composition of rare earth metals to minimize the ringing properties of titanium. Doing so allowed DUNU to bring out the natural, ‘colorless’ timbre of its one-of-a-kind driver.
The inner facet of the housing bodies preserves distinct lines created by the machining process, creating natural contour lines much like a topographic map.
The moon is packed with copious amounts of precious Titanium ore, and these contours delineate a denuded surface landscape that defines LUNA.
Every component of LUNA's housings has been carefully considered, to maximize structural rigidity and to minimize cavitary resonances.
Our parts tolerances have been shrunken down to the smallest possible to ensure that its components, like those in a moonfaring spacecraft, are securely sequestered from the environment.
The acoustic grade rolled foil beryllium at the heart of LUNA's 10 millimeter speaker module is sourced from Materion Corporation (née Brush Wellman Electrofusion), the world's foremost extractor and processor of beryllium metals.
Beryllium is believed to be the ideal speaker material. An extremely high stiffness-to-mass ratio (high Young's modulus, low density) allows beryllium to possess a very high speed of sound at over 12,000 meters per second, around two and a half times faster than other commonly used cone/diaphragm materials like aluminum.
The very low Poisson's ratio of beryllium potentiates its ability to maintain pistonic motion of the driver, even at the edges of a diaphragm, and in turn preserves the imaging properties of the music being reproduced. The very high Debye temperature of beryllium also means the lattice structure of the beryllium metal is retained even at very high frequencies, translating to remarkable treble evenness. All these unique properties of beryllium enable audio designers to gain extra octaves of clean, non-distorting, non-ringing, high-resolution sonic output at both ends of the sonic spectrum.
Suspension and Mounting
A one-of-a-kind diaphragm material begets an one-of-a-kind driver design. The major engineering hurdle DUNU had to overcome during the development of the LUNA was the process of getting the rolled foil beryllium diaphragm to be bonded circumferentially to a very thin polyurethane suspension.
Doing so required formulating bespoke glues, lightweight and thin enough so as not to impact the total weight of the acoustic system, and reliable enough to be glued evenly against a very thin lip and still confer enough durability to sustain the immense mechanical energy delivered during driver excursion.
To harness and control the motion of the beryllium foil, LUNA's N52 Neodymium magnetic system was custom-ordered to impart much higher magnetic flux across the European-imported CCAW voice coil, especially when compared to conventional magnet systems.
To prove our driver design, we carried out high-speed vibrometry of LUNA's pure beryllium foil driver at a third party site.
With fully preserved pistonic motion across the entire driver, it only made sense that LUNA was tuned to a reference sound signature --- deep and natural imaging, even and smooth from top to bottom, and maximized for extension at both ends.
The result is the most supremely detailed, transparent, sumptuous sounding earpiece ever crafted by DUNU, and our best representative of beryllium’s full sonic potential.
- FREQUENCY RESPONSE: 5 Hz - 40 kHz
- TOTAL HARMONIC DISTORTION: 0.2% at 1 kHz
- NOMINAL IMPEDANCE: 16 Ω
- SENSITIVITY: 110 dB at 1 kHz
- DRIVE MODULE: 10 mm Acoustic-Grade Pure Beryllium Rolled Foil with Polyurethane Suspension
- HOUSING MATERIAL: Titanium Alloy, Grade 5 (Ti-6Al-4V, TC4, with modified rare earth metal formulation)
- NET WEIGHT: 10.3 g
- CABLE LENGTH: 1.2 m
- CABLE MATERIAL: Mixed Strands of Furukawa Electric Ohno Continuous Cast (OCC) Copper & DHC Silver, with Silver-Plated OCC Copper Shield Surround
- CABLE CONNECTOR: Patented Catch-Hold® MMCX Connector
- PLUG CONNECTOR: Patented DUNU Quick-Switch Modular Plug System