FiiO FT7 Flagship Open Back Planar Over Ear Headphones

The FiiO FT7 is FiiO’s flagship open-back planar magnetic headphone. A self-developed 106mm planar driver with an ultra-thin 1µm diaphragm and FiiO’s patented gold and silver coating, a patented uniform magnetic field from 18 N52 magnets in a push-pull array, and natural zebrawood grilles deliver what FiiO calls a highly detailed yet charmingly rich sound. A carbon-fibre frame keeps it to just 427g, and it comes with a cryogenically treated 6N copper cable, two sets of ear pads and a linen storage bag.

A 106mm planar driver, built like a big speaker

FiiO’s designer set out to bring the feel of a 15-inch loudspeaker to headphones: abundant energy, sound that comes effortlessly, and bass you can feel pushing air. The result is a newly developed 106mm full-size planar driver that uses several of FiiO’s patented acoustic technologies to extend the ultra-low-frequency response that planar headphones are capable of. Frequency response runs from 5Hz to 40kHz.

A 1µm diaphragm, made with semiconductor techniques

After two years of research, FiiO created a class-leading 1µm diaphragm on a high-performance PET substrate. Even the step from 2µm to 1µm makes an audible difference at high speeds: the lighter film responds with lightning speed, reproduces subtle ultra-high frequencies and gives exceptional dynamic range. The conductive trace is applied with a 28nm-grade process borrowed from semiconductor coating: in a vacuum of 6.6 × 10⁻³ Pa at 120°C, the trace material is ionised and built up on the film to the ideal thickness, which also makes it far more durable. FiiO aged the drivers for more than a year in its labs without any detachment, separation or broken traces, and the sound stayed within specification.

Patented gold and silver coating

FiiO’s patented multi-layer coating (patent ZL2024205488218) selectively applies 24K gold and pure silver to the driver, combining the strengths of both metals. FiiO says the gold improves the diaphragm’s damping for a charming low end, while the silver brings clarity and purity to the treble.

A patented uniform magnetic field

FiiO’s finite element analysis showed that traditional rectangular magnets create an uneven field, so parts of the diaphragm are pushed harder than others, causing break-up and distortion. The FT7’s patented design (ZL202420884963.1) uses rounded-corner magnets in an optimised layout so the whole diaphragm is evenly driven. It also widens the field, keeping the large driver sensitive while saving weight. Nine N52 neodymium magnets sit on each side of the diaphragm, 18 per driver in a dual-sided push-pull circuit with a flux of up to 1.5T, for abundant energy, excellent transients and textured bass.

Natural zebrawood and carbon fibre

The grilles are zebrawood from the West African highlands, from trees that typically grow at about 1,600m, with the flowing stripes that give the wood its name. Each grille strip lines up with the magnets behind it to reduce reflections. Much of the frame is lightweight, high-strength carbon fibre, so the FT7 weighs only about 427g, light for a high-end planar, with an earpad pressure of 4.2N. Three-axis rotating cups and a 12-step ball-bearing slider help it fit comfortably.

A cryogenically treated 6N copper cable

The cable was developed for the FT7’s sound. Its 6N OCC monocrystalline copper (99.99998% pure) is kept at −192°C in liquid nitrogen for seven days, which relieves internal stress and tightens the crystal boundaries for better conductivity and clarity. PFA insulation, with a dielectric constant of only 2.1, also damps vibration. Planar headphones can sound a little dry, and FiiO tuned this cable to keep the resolution while adding a touch of richness to the mids and bass. It is about 3m long, with dual 3.5mm connectors and a 4.4mm balanced plug; adapters to 4-pin XLR and 6.35mm are included.

Two sets of pads and a linen bag

Lambskin pads (fitted) give clear sound, a wide soundstage and plenty of detail. The breathable fabric pads are kind to skin, add atmosphere to the music and depth to vocals. A storage bag in soft, tightly woven Yaoli linen, which resists wear and pilling, keeps the FT7 safe.

The FT7 is Hi-Res Audio certified (Japan Audio Society and CEA), won a VGP 2025 Summer Life Style award, received five stars from hifi.nl and is a Headfonics Writer’s Choice for 2025.

Good to know

• Open-back: sound escapes and outside noise comes in, so the FT7 is best at home rather than on the move.
• At 25Ω and 94dB/mW it isn’t hard to drive, but a capable desktop amplifier such as the FiiO K17 brings out its best.
• FiiO’s other planar headphones: the FT1 Pro and FT5.
• In the box: FT7, headphone cable, XLR-4 (male) to 4.4mm (female) adapter, 4.4mm to 6.35mm adapter, lambskin pads (fitted), breathable fabric pads, linen storage bag and quick start guide.