Inner ear headphones



METAL 01 inner Hi-Resolution Audio headphones

The High Resolution Headphones



Desire to Deliver Sound
that Resonates in the Heart

In Quest for the Original Sound – a new approach to JVC’s eternal quest. Our objective is to reduce the distance between artists and listeners to the bare minimum. We want to convey all the passion the performer pours into the music, including the most delicate sounds. METAL was developed in the pursuit of improvement in experiencing what is in the performer’s heart. A solid, rich and delicate sound that reaches the listener's heart can be heard. With our relentless curiosity for the better, we found a way to a new musical experience.

Shimmering Full Stainless-Steel Body Delivers Unmatched Sound Quality

The headphone body is all stainless steel to achieve solid sound.
High strength and hardness of stainless steel works to sweep away sound impurity.
And the headphone’s metallic shimmer visually conveys solidity.

D3 Driver Unit

A newly developed D3 driver unit is employed for the main part that controls the sound of the headphones.
D3 stands for “dignified, distinct, and delightful”.
As the words describe, the driver unit delivers sound that is distinct in its details, delightful to the ears.

Spiral Dot + <Plus> Ear Tip

D3 Driver Unit

JVC’s original spiral dot ear tip, which achieves clear sound by diffusing reflected sound within the ear tip by arranging dimples inside the cylinder, has been improved to Spiral Dot+ Ear tip that features a new form and material to achieve even better sound. The new ear tip material features mechanical properties similar to the skin to offer a natural fit that makes one forget about the existence of the ear tip.

Fine Adjust Rotation Mechanism

As no two ear shapes are identical, JVC developed a new mechanism called Fine Adjust Rotation featuring a nozzle that rotates 360 degrees and adjusts to any angle. Additionally, the mechanism supports two wearing styles – normal and ear hook – so the user can find the optimum position and most comfortable fit.

J Mount Nozzle Replacement System

J Mount Nozzle Replacement System

Sound can be customized to the user’s favorite tone by replacing the nozzle with one of the three nozzles each made of different materials.

MMCX Detachable, L/R Independent High-grade Grooved Cable

Left and right channels are completely independent, from the tip of the headphones to the plug. In addition to improved separation and cleaner sound, the high-grade grooved cable assures the clean transmission of the full range of sound.

Story of METAL


With Metal, we focused on the minute details of sound. What we aimed for was to eliminate the fuzzy part of the sound and express its outline by reproducing the details to let the sound stand out.
The most prominent part about this product was the development of a new driver unit called the D3 driver. D3 stands for “dignified, distinct, and delightful” and these words describe the conceptual direction of this driver unit.

In order to realize the three D’s, the driver unit is embedded with a specially developed diaphragm called DLC Dome Dual Carbon. This diaphragm is composed by layering four different materials – two high molecular polymers and two amorphous carbons. At the center of the diaphragm is a dome area using polyethylene naphthalate (PEN), which is a material offering higher strength than PET. This dome area is coated with a diamond-like carbon (DLC) film for stability and strength.

PET, which offers relative flexibility, is applied on the outer surface of the dome, and carbon black (CB) has been used for the damping material. This combination of a tough dome and flexible outer material allows the most important section of diaphragm “dome” to perform with solid strokes and accurate motion. This structure enabled crisp yet not-too-edgy sound that feels just right for your ears. Changing the material just for that small diaphragm section may seem like a rather nonsensical and time-consuming procedure, however, for the Metal, we arrived at a combination of two types of polymers and two types of carbon. And this combination is a characteristic that can only be found with Metal.


Sound can be adjusted by replacing nozzles attached to the HA-FD01. The nozzles are made of different metals that can be replaced to change the tone. Three different nozzles – titanium, stainless steel, and brass – come supplied with the HA-FD01. Identical acoustic filter specifications are used so the user can simply enjoy the different tones achieved from different materials.
The frequency response remains the same even when the nozzles are replaced. Interestingly though, what you hear from your ears sounds different when the nozzles are replaced. That’s because each metal material has its own unique acoustics.
There are no other earphones where you can feel the difference in sound depending on the characteristics of a material.

The nozzle can be replaced as if exchanging a camera lens. Overall, we had a hard time making sure there were no negative effects since the nozzle section greatly influences the sound quality.
We also carefully considered safety. A simple screw-in method could have been applied for nozzle attachment; however to avoid inadvertent removal of the screw during use, we adopted such a complicated structure for the nozzle attachment.


Human ear canals are never straight but intricately curved and bent. Therefore, we adopted a rotating nozzle structure. If you adjust it to the angle that best suits your ears, the sound and wearability will be much better.
The rotating nozzle is devised to not adversely affect the sound even if the angle is changed. Not only the angle of the nozzle can be adjusted but also the position of the cable can be changed as the nozzle is designed to freely rotate 360 degrees. So, you can wear it in Normal Style or Ear Hook Style as shown in the diagram below.


The earphone comes supplied with Spiral Dot+ Earpiece, which uses a new material with mechanical properties like human skin. Like the original Spiral Dot that is designed to eliminate sound mudding with dots, we devised the Spiral Dot+ earpiece with a new material and refined the form to achieve better sound quality and wearability.
When you touch the Spiral Dot+ earpiece, you can tell that it has a special, dough-like texture. This special texture not only offers the sense of slight stickiness but also provides an excellent fit that doesn’t put any strain on your ears.


Conventional 4N OFC is used for the cable itself, however we’ve changed the composition of the core to improve the reproducibility of details while, at the same time, not losing the dynamic feel.
Another feature is complete independent left and right channels from the headphones to the MMCX plug. As a result, channel separation has been improved, offering excellent spatial expression.
Soldering is not applied to the branching point because solder changes the sound quality. By reducing the amount of soldering applied, we tried to transmit the sound without impacting the quality received from the player.
The cable itself is a bit bulky, however we made it as soft as possible. A lot of effort went into the cable, like adjusting the hardness of the coating, making it as flexible as possible considering ease of use, and maintaining durability even if it is bent… and so on.


As for the sound of HA-FD01, we carefully tuned it by placing emphasis on clarity while stressing superior wearability.
The full stainless-steel body may seem heavy when you hold it, but along with the cables and earpieces, we hope people will hold it, see it, and experience it for themselves.

  • Spiral Dot Plus earpiece with new material for a natural fit and improved expressiveness
  • D3 driver unit with titanium-coated case delivers solid high-quality sound
  • High-grade grooved cable with isolated L/R realizes clear and natural soundscape
  • MMCX terminal
  • Full stainless steel body delivers lively highs and well-defined bass
  • Fine Adjust Mechanism provides optimal fit
  • J-Mount Nozzle System allows sound customization with three types of nozzles in different materials
Technical Specifications
Product Support
Technical Specifications
Audio Specifications
Dynamic frequency response range
8 - 52000 Hz
Driver Type
D3 driver unit
16 Ω
Max. Input Capability
200mW (IEC)
Headphone Cord
Detachable cable with MMCX
3.94 feet
Gold plated 3,5mm mini-jack
In the Box
Carrying case
Spiral Dot Earpieces
Yes, 5 pairs(S/MS/M/ML/L)
Product Support