In addition, they carefully selected several unique features to realize the most natural and beautiful sound in all of their signature Flat4 series. Let's take a closer look.

Flat4-KAEDE III/AKAKAEDE III Balance/Stereo Mini-plug


Why Ocharaku Introduced CNF for Flat4 KAEDE III?
Major Characteristics of CNF (Cellulose Nanofiber)
Several Stand-out Features
Made with Japanese Wooden Craftsmanship
Differences Between KAEDE III and AKAKAEDE III
"FLAT4" Describes How Ocharaku Technology Works
Limited-time Novelty Offer
Unboxing Video: Ocharaku Flat4 KAEDE III Headphones

Why Ocharaku Introduced New Material CNF for Flat4 KAEDE III?

Here is a brief introduction of CNF and the reason why Yamagishi,
the founder of Ocharaku, introduced it for Flat4 KAEDE III.

First off, biomass material CNF stands for "Cellulose Nanofiber,"--a very fine fiber defibrated to the nano level of several hundredths of a micron and smaller.CNF is derived from dietary fiber requiring cutting edge technology to obtain the material.

Photomicrograph of CNF (Cellulose Nanofiber)

close-up on cnf  image
*The photo is provided by Industrial Research Institute of Shizuoka Prefecture.

Major Characteristics of CNF (Cellulose Nanofiber)

One of the most notable characteristics of CNF is, compared to steel, it is one-fifth lighter and over five times stronger. Moreover, CNF avoids unnecessary resonance as it has a low at Q factor--a parameter describing the state of vibration.

Such characteristics were ideal for a diaphragm, good enough for Yamagishi to want to experiment this new material with their new product. However, while CNF does have superior properties, it was still a difficult task to optimize the compositions of CNF to apply in the diaphragm of KAEDE III.

After countless attempts, by strengthening the necessary parts of the diaphragm with CNF, Ocharaku finally succeeded to co-exist the expansion of the high frequency range and a powerful low frequency range.

Several Stand-out Features for Ocharaku Flat4 KAEDE III

For KAEDE III, Ocharaku incorporated several stand-out features (incl. CNF) to harmonize the sound beautifully.
  • Solid maple (Kaede) cabinet with urushi lacquer finishing
  • Grooved inside cabinet for controlled resonance
  • Correction tube with urushi lacquer finishing
  • New element with CNF-contained-diaphragm

Along with CNF, these features are also unique to KAEDE III, each contributing for KAEDE III to have the most natural and beautiful sound out of all the Flat4 lineup.

Quantities are strictly limited to only 200 pieces worldwide due to the rare materials used. Don't miss out on this chance for these limited products.

Furthermore, just like the previous Flat4 lineup, KAEDE III feature highly acclaimed Ocharaku original technology detailed below.

Flat4-KAEDE III/AKAKAEDE III Balance/Stereo Mini-plug

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Made with Japanese Wooden Craftsmanship

The center cabinet is made of solid maple. Coated with a layer of natural raw lacquer, which is a key element contributing to the impressive aesthetics and the most crystal clear sound.

Each piece is specially selected and handcrafted by master craftsmen from OAK VILLAGE, a woodcrafts company established in 1974 in the forest of Hida-Takayama.

Features of Flat4 KAEDE III/AKAKAEDE III Balance/Stereo Mini-plug

A phase correction tube, a key technology of Ocharaku detailed later, applies vibration-resistant coating to suppress the howling noise. It realizes minimizing sound deterioration and warmer and softer high-tone range.

Features of Flat4 KAEDE III/AKAKAEDE III Balance: 4.4mm NIPPON DICS-made Plug

Applies a 4.4mm 5-pole gold plated non-oxidized copper balanced plug, which is made by NIPPON DICS. It highly enhances the unique sound the KAEDE III material has.


Differences Between KAEDE III and AKAKAEDE III

Flat4 KAEDE III/AKAKAEDE III can be divided into two types, depending on the color of the phase correction tube:
Black is for KAEDE III while Red is for AKAKAEDE III.

It also can be divided into two types, depending on effective length of the ear canal: KAEDE III is set for 28mm while AKAKAEDE III is set for 30mm.

The length of the ear canal is generally referred to as 25 to 30mm as shown below, and the length set for Flat4-KAEDE III is relatively appropriate for more people than that of Flat4-AKAKAEDE III. Sound quality will be better if the effective length gets closer to your ear canal length.

References on the ear canal length 

The Human Ear Canal – V (
Ear canal (Wikipedia)

Flat4-KAEDE III/AKAKAEDE III Balance/Stereo Mini-plug

"FLAT4" Describes How Ocharaku Technology Works

FLAT4 is an abbreviation of "Full range 2-element 4-way effect," and it shows how Twin Equalized Element System, one of their patented technologies, works. It realizes the wide frequency range, especially delivering the bass deeper than conventional closed dynamic headphones, as well as the spread of sound just like open-air ones.

Along with that, it dramatically proves two problems conventional canal headphones have: characteristically high-intensity noisy sound and masking effect in certain specific high-tone range both mainly caused by the closed tube resonance of the ear canal.

Followings are the details of how "4-way effect" works.  

1st effect

Placement of two elements ("2-element") opposed to each other cancels mechanical vibration due to reaction of vibration system. It realizes deeper bass tones than that of conventional closed types.

2nd effect

In low and mid range tones, parallel drive of the twin elements enhances sound pressure sensitivity.

3rd effect

The phase correction tube suppresses the closed-ear canal resonance and eliminates the masking effects, dramatically improving sounding in mid- and high-tone range.

4th effect

By eliminating acoustic resistors and applying small elements, it dramatically improves ultra-high-tone range. Also it realizes the spread of sound like open-air types.

Flat4-KAEDE III/AKAKAEDE III Balance/Stereo Mini-plug


Cabinet Center: Solid Maple with "Fuki Urushi" (wiped lacquer) finishing
Element 010e007 (cellulose nanofiber-based diaphragm applied) 10mm Dynamic Type x 2 (for each ch)
Acoustic System Twin-Equalized-Element System
Sound Pressure Level 104 dBSPL/mW
Frequency 3.5Hz to 45kHz (High-resolution compatible)
Maximum Input 400mW
Impedance 18 Ohms
Weight 17g / 21g (balance)
Cable 1.2m (Y type)
Plug 3.5mm Stereo Mini / 4.4mm 5-pole (balance)


  • Comply T-200 Ear Tip x 2 (Size: M, L / M is attached to the main unit)
  • Silicone Ear Tip (final, E type) x 5 (Size: SS, S, M, L, LL)
  • Cleaning Cloth
  • Wooden Casing (Maple & Paulownia Solid Wood)
  • Instruction Manual / Warranty Card
  • L type Cable Adapter (incl. Stereo Mini type only)

Other Features

  • Applies tangential-less vibration plates, reducing the distortion on mid- and high-tone range.
  • Strong magnetic circuit with neodymium magnet, pure iron, and yoke improves sensitivity and sound quality.
  • Applies specific CCAW voice coil, greatly improving input resistance.

Limited-time Novelty Offer

For purchasers of Ocharaku Flat4 KAEDE III/AKAKAEDE III, we will send you a novelty accessory. This offer is run with first-come-first-served basis, and ends when the stock is run out.

Unboxing Video: [Unboxing] Ocharaku Flat4 KAEDE III Headphones

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Flat4-KAEDE III/AKAKAEDE III Balance/Stereo Mini-plug

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