FiiO Jade Audio JT9 Over Ear Headphones

The FiiO Jade Audio JT9 is an open-back planar magnetic headphone that brings FiiO’s own planar technology to a lighter, foldable design. Its next-generation 95 × 86mm driver has a 1µm diaphragm with a sapphire and aluminium dual coating, made with a 28nm-grade process and driven by a patented uniform magnetic field, for deep bass extension, fine treble detail and a natural, expansive soundstage. At 95dB/mW it is easy to drive from a phone and dongle, it weighs only 365g, and it comes with 3.5mm and 4.4mm balanced cables and a water-resistant case. It is Hi-Res Audio certified, in black or deep brown.

A next-generation 95 × 86mm planar driver

FiiO’s own planar driver measures 95 × 86mm, a large radiating area for deep bass extension and a natural, expansive soundstage. The planar design spreads the driving force across the whole diaphragm for even, controlled movement, and the open back lets the sound breathe for a natural sense of space between instruments.

A 1µm diaphragm

The diaphragm is just 1µm thick, against 3µm or more in typical full-size planar headphones. Its low mass gives a lightning-fast transient response that captures the finest treble detail.

Sapphire and aluminium: a dual coating

Two coatings balance excellent conductivity with high rigidity for finer resolution. Lightweight aluminium improves the voice coil’s conductivity and lowers the impedance, making the JT9 easier to drive and giving it a wider dynamic range. Sapphire’s exceptional hardness stiffens the diaphragm, improving high-frequency resolution and clarity and contributing to the JT9’s distinctive tone.

28nm-grade manufacturing and a uniform magnetic field

A semiconductor-grade, 28nm-class manufacturing process forms the voice coil with higher accuracy and makes it more durable. FiiO’s patented uniform magnetic field uses an optimised layout of strong magnets so the whole diaphragm moves in sync, suppressing distortion at its source.

Easy to drive

With a sensitivity of 95dB/mW (112dB/Vrms) at 1kHz and an impedance of 20Ω, the JT9 lowers the bar for driving a planar: a smartphone with a portable DAC/amp dongle drives it easily, though a dedicated amplifier still helps you get the most from it.

365g, foldable and adjustable

Typical full-size planar headphones weigh over 400g, which makes head pressure and neck discomfort more likely on long sessions. The JT9 is about 40g lighter at 365g (without cable), so you can stay immersed in music for hours. The earcups rotate and fold flat into a compact shape about 170 × 135 × 106mm, easy to store at home or carry with you. For a good fit, the cups fold through 90°, swivel 35° horizontally and tilt 45°, and the headband slides through 38mm.

Two cables, tuned for the mid-bass

Both a 3.5mm single-ended cable and a 4.4mm balanced cable are included, made from 22AWG high-purity oxygen-free copper and, according to FiiO, specially tuned for mid-bass performance. Each is about 1.5m long and connects to the earcups with dual 3.5mm TS plugs, and a 6.35mm adapter fits standard headphone sockets. Use the 3.5mm cable with phones, dongles and most headphone outputs, and the 4.4mm cable with balanced players, DAC/amps and amplifiers.

A dedicated water-resistant case protects the folded JT9 when you take it with you.

Good to know

• Open-back: sound passes in and out, so the JT9 is best where a little sound leakage doesn’t matter.
• The JT9 shares its 95 × 86mm driver size, 1µm diaphragm and sapphire–aluminium coating with FiiO’s FT1 Pro, in a lighter, foldable body. For a more affordable planar, see the Jade Audio JT7.
• A dongle such as the FiiO KA13 (3.5mm and 4.4mm balanced) makes a good portable partner.
• In the box: JT9, 3.5mm cable, 4.4mm balanced cable, 6.35mm to 3.5mm adapter and water-resistant storage case.