FiiO Jade Audio JT9 – Lightweight with a Large Planar Driver
FiiO has designed the FiiO Jade Audio JT9 Open-Back Planar Headphones around a proprietary 95 × 86 mm planar-magnetic driver with an exceptionally thin 1 μm diaphragm. Sapphire and aluminium coatings, semiconductor-grade manufacturing and a patented magnet arrangement are intended to keep the large diaphragm under precise control. With a sensitivity of 95 dB/mW, a foldable 365 g construction and two supplied cables, the JT9 is not restricted to conventional desktop headphone systems.
- The FiiO Jade Audio JT9 brings a large-format planar-magnetic driver into a headphone that weighs 365 g, folds for storage and can be used with compact DAC/headphone amplifiers as well as desktop equipment. Its open design makes it primarily a choice for undisturbed listening at home, in the office or in a hotel room, while the supplied 3.5 mm and balanced 4.4 mm Pentaconn cables cover the most important portable and stationary connections.
Open-back planar-magnetic headphones tend to demand a degree of commitment. Their large diaphragms and elaborate magnet structures often result in considerable weight, while some models also require a capable stationary headphone amplifier before they can perform as intended. Guangzhou FiiO Electronics Technology Co. Ltd. has approached the FiiO Jade Audio JT9 Open-Back Planar Headphones with a rather different set of priorities.
The JT9 retains the defining ingredients of a full-size planar design, including a proprietary 95 × 86 mm driver, yet weighs 365 g and can be folded for transport. Its sensitivity of 95 dB/mW is intended to make operation with portable Hi-res audio players or smartphones paired with a compact DAC/headphone amplifier entirely practical. The most technically distinctive element, however, is the 1 μm diaphragm, which combines sapphire and aluminium coatings with an unusually precise conductor structure.
Key Facts FiiO Jade Audio JT9 Open-Back Planar Headphones
- Open-back over-ear planar-magnetic headphones
- Proprietary 95 × 86 mm planar-magnetic driver
- 1 μm diaphragm
- Sapphire and aluminium dual coating
- Patented magnet arrangement for a uniform magnetic field
- Semiconductor-grade 28 nm manufacturing process
- Sensitivity of 95 dB/mW
- Weight of 365 g
- Foldable construction
- 3.5 mm stereo mini-jack and 4.4 mm Pentaconn cables included
- Black and Deep Brown finishes
- Water-resistant carrying case
- Hi-res Audio certified
A large planar driver without the usual bulk
The central component of the FiiO Jade Audio JT9 is a planar-magnetic driver developed by FiiO and measuring 95 × 86 mm. Unlike a conventional dynamic headphone driver, which uses a voice coil to apply force to a specific area of the diaphragm, a planar design distributes its conductor structure across much of the diaphragm surface. The surrounding magnet system can therefore drive a substantially larger area.
FiiO associates the large effective surface with extended bass reproduction and a spacious, natural presentation. These are the manufacturer’s stated acoustic objectives rather than findings from a listening test. From a technical perspective, the larger diaphragm area can move the required volume of air at low frequencies without relying on particularly wide excursions.
What makes the JT9 unusual is the attempt to package this large driver in a comparatively manageable headphone. At 365 g, it remains relatively light for an open planar-magnetic model of this size. The ear cups can also be folded, making the headphones easier to store in the supplied carrying case.
The open-back construction nevertheless defines where the JT9 can sensibly be used. It provides little isolation from outside noise, while music remains clearly audible to people nearby. This is therefore a headphone for listening at home, in a quiet office or in a hotel room rather than on public transport or in other shared spaces.
A diaphragm only 1 μm thick
The diaphragm used in the FiiO Jade Audio JT9 measures just 1 μm in thickness. Reducing its mass allows it to change direction with less inertia, which is intended to support a rapid transient response and more precise reproduction of fine high-frequency information.
Low moving mass is particularly important in a planar-magnetic driver because the entire diaphragm should follow the signal evenly and without unnecessary delay. FiiO says the JT9’s construction is designed to reproduce small signal changes accurately while maintaining a fast response across the diaphragm surface.
A membrane this thin must also remain sufficiently stable while moving. Simply reducing its thickness would achieve little if sections of the diaphragm flexed or behaved differently under load. FiiO therefore combines the lightweight film with two complementary coatings.
Sapphire and aluminium fulfil different roles
FiiO describes the diaphragm treatment as Dual-Coating Technology. Aluminium provides the electrical conductivity required by the conductor structure, while the sapphire coating is intended to increase the rigidity of the exceptionally thin diaphragm.
The two materials are therefore not included for the same purpose. Aluminium supports efficient electrical operation, whereas sapphire is intended to prevent unwanted deformation as the diaphragm moves. According to FiiO, this combination contributes to finer resolution and more controlled behaviour without adding excessive moving mass.
Semiconductor-grade precision for the conductor structure
The conductor tracks applied to the diaphragm are produced using what FiiO calls a “28 nm-grade process technology”. The description refers to a level of precision associated with semiconductor production rather than to a conventional headphone manufacturing method.
Finer and more accurately defined conductor structures should allow the driving force to be distributed more consistently across the diaphragm. FiiO also points to improved mechanical stability and greater durability of the combined diaphragm and conductor assembly.
This manufacturing detail is significant because a planar driver depends upon the interaction between its conductor pattern and magnet arrangement. The accuracy of those structures directly influences how evenly the diaphragm can be driven across its entire surface.
A uniform magnetic field to control distortion
The planar driver is completed by a magnet system based on a patented arrangement. FiiO positions the individual magnets to generate a strong and as uniform as possible magnetic field across the full diaphragm area.
The objective is to make every section of the diaphragm react synchronously to the music signal. If individual areas move differently, the diaphragm can deform and create distortion. FiiO’s magnet configuration is intended to limit these irregular movements within the driver itself and maintain tighter control over the large surface.
The thin diaphragm, dual coating, precision conductor structure and magnet arrangement therefore form a single technical concept. Each part addresses a different aspect of controlling a very light but unusually large moving surface.
Designed for compact DAC/headphone amplifiers
A sensitivity of 95 dB/mW should make the FiiO Jade Audio JT9 less demanding than some large planar-magnetic headphones. FiiO explicitly names smartphones used with a portable DAC/headphone amplifier as a suitable source, alongside portable Hi-res audio players and conventional desktop systems.
The JT9 is therefore not intended to depend exclusively on a powerful stationary headphone amplifier. A compact USB DAC or DAC/AMP dongle should provide a viable route to operation, which considerably broadens the range of potential systems.
Sensitivity alone does not provide a complete picture of a headphone’s electrical requirements, however. At the time of publication, FiiO has not specified the impedance of the new model. It is therefore possible to describe the intended application and published sensitivity, but not to make a complete assessment of the amplifier load.
Two cables supplied as standard
FiiO includes two detachable connection cables with the JT9. The first terminates in a 3,5 mm stereo mini-jack and is suitable for many portable players, DAC/AMP dongles and conventional headphone outputs.
The second cable uses a balanced 4.4 mm Pentaconn connector. This provides a direct connection to suitably equipped portable players as well as balanced outputs on stationary headphone amplifiers, without requiring the buyer to purchase another cable immediately.
According to FiiO, the cables have been tuned specifically with reproduction in the mid-bass region in mind. This remains a manufacturer claim, but it shows that the supplied accessories are regarded as part of the complete acoustic package rather than merely functional additions.
Foldable, but still an open-back headphone
The folding mechanism and 365 g weight make the JT9 easier to transport than many large planar-magnetic designs. FiiO also supplies a water-resistant carrying case to protect the headphones and cables during storage or travel.
That does not turn the JT9 into a conventional commuting headphone. Its open ear cups use large external grilles and neither keep environmental noise out nor prevent music from escaping. The transportable construction is instead useful for listeners who want to move a serious open-back headphone between home, office and temporary accommodation.
Black first, Deep Brown to follow
The FiiO Jade Audio JT9 will be offered in two finishes. Black is scheduled to reach the market first, while the Deep Brown version is expected at a later date. Both variants display the open acoustic design through the prominent grilles on the outside of the ear cups.
FiiO also lists Hi-res Audio certification among the product’s features. This confirms compliance with the technical criteria associated with that certification, although it should not be interpreted as an independent judgement of the headphone’s sound quality.
The Most Important Advantages at a Glance
- Large-format planar driver: The 95 × 86 mm driver provides a substantial effective diaphragm area.
- Exceptionally low moving mass: A diaphragm thickness of only 1 μm is intended to support rapid and precise movement.
- Complementary diaphragm coatings: Sapphire provides rigidity, while aluminium supplies the necessary electrical conductivity.
- Controlled diaphragm movement: The patented magnet arrangement is designed to drive the entire surface as uniformly as possible.
- Broader amplifier compatibility: A sensitivity of 95 dB/mW allows FiiO to envisage operation with compact portable DAC/headphone amplifiers.
- Moderate weight: At 365 g, the JT9 remains comparatively light for a planar-magnetic headphone with such a large driver.
- Easier storage and transport: The folding construction and supplied water-resistant case make moving the headphones between listening locations more practical.
- Two connection options included: Both 3,5 mm stereo mini-jack and balanced 4,4 mm Pentaconn cables are supplied.
Price & Availability
The FiiO Jade Audio JT9 Open-Back Planar Headphones will initially be offered in Black and, according to Guangzhou FiiO Electronics Technology Co. Ltd., should shortly become available from authorised specialist retailers. The Deep Brown finish is scheduled to follow at a later date.
The anticipated price of the FiiO Jade Audio JT9 Open-Back Planar Headphones is € 199,-. A formally confirmed recommended retail price for the DACH region was not yet available at the time of publication.
Getting to the Point
The FiiO Jade Audio JT9 has a clearly defined purpose. Its 95 × 86 mm planar driver, 1 μm diaphragm, dual coating and carefully arranged magnet system provide the technical substance expected of an ambitious open-back headphone, but FiiO has not confined that technology to a heavy, desk-bound design.
A weight of 365 g, folding ear cups, two supplied cables and a sensitivity of 95 dB/mW make the JT9 relevant to listeners who want to use a planar headphone with compact equipment or in more than one location. Its open construction naturally limits where that can happen, and the missing impedance specification leaves one electrical parameter unanswered. If the anticipated price of € 199,- is confirmed, however, FiiO will have positioned a technically elaborate planar-magnetic headphone at a notably accessible level.
| Product | FiiO Jade Audio JT9 Open-Back Planar Headphones |
|---|---|
| Price | probably € 199,- |
Technical Specifications
| Product | FiiO Jade Audio JT9 Open-Back Planar Headphones |
|---|---|
| Type | Open-back over-ear headphones |
| Driver principle | Planar-magnetic |
| Driver | 95 × 86 mm |
| Diaphragm thickness | 1 μm |
| Diaphragm coating | Sapphire and aluminium |
| Manufacturing | Semiconductor-grade precision process, 28 nm-grade |
| Magnet system | Patented arrangement for a uniform magnetic field |
| Sensitivity | 95 dB/mW |
| Weight | 365 g |
| Construction | Foldable |
| Connection cables | 3.5 mm stereo mini-jack and 4.4 mm Pentaconn |
| Finishes | Black; Deep Brown available later |
| Transport | Water-resistant carrying case |
| Certification | Hi-res Audio |
| Company | Guangzhou FiiO Electronics Technology Co. Ltd. |
| Brand | FiiO |
| Distributor | NT Global Distribution GmbH |
| Brand | Guangzhou FiiO Electronics Technology Co. Ltd. |
|---|---|
| Manufacturer | FiiO |
| Distribution | NT Global Distribution GmbH |
| More about this manufacturer at HiFi BLOG |
