FiiO reveal FX17 flagship in-ear-monitor headphones

Hot on the heels of the FT7 flagship over-ears comes the latest innovation from FiiO, 18 years in the making with three types of driver offering a generational step forward in IEM design...

March 24, 2025

The FX17 features a design of one dynamic driver, four balanced armature drivers and eight electrostatic drivers per side. A five-way crossover has been precisely tuned to balance energy distribution among the driver and ensures each unit operates in its optimal state, resulting in a bigger soundstage and more natural sound.

A USB-C cable in the box also mean the flagship IEMs can be used with all modern Android and iPhone devices out of the box...

Eight electrostatic drivers

Electrostatic drivers have exceptional high-frequency extension easily reaching 50kHz and sense of air that gives the listener a grander soundstage. Their downside is that their sensitivity is only 99dB/mW, which is low compared to the 110dB/mW sensitivity typically found in balanced armature and dynamic drivers - leading to the 'masking effect.' The FX17 uses 8 electrostatic units to increase sound pressure levels in order to make the electrostatic drivers more audibly perceptible as they handle the high and ultra-high frequencies above 6kHz.

Four custom Knowles BA drivers

The FIIO FX17 uses Knowles balanced armature driver composite units that handle the mid and high-frequency sounds. Each of the composite balanced armature driver units is divided into two parts, one part responsible for mids and the other for mid-high frequency – leading to denser mids and a more transparent sound and allows them to transition seamlessly into the electrostatic drivers. To achieve higher flagship-level vocal performance, FIIO, in collaboration with Knowles, custom-developed a 'Midrange Enhanced Balanced Armature Unit.' Acoustic vents have been added to the rear cavity of the balanced armature, which provide more sound energy reserves for the mid-frequency balanced armature unit to further tap into the driver’s advantages.

Lithium-magnesium alloy diaphragm dynamic driver

Lithium-magnesium alloy is lightweight, rigid and has a density of 1.6g/cm³ - making it an ideal material for a dynamic driver diaphragm. When reproducing high-frequency signals with rapid vibrations, the lithium-magnesium alloy diaphragm has excellent mechanical properties thanks to its high internal damping – leading to significantly reduced intrinsic frequency resonance and distortion.

Pure titanium construction

The FX17 features a minimalist aesthetic, with a classic and natural curved cavity. The FX17’s 'ear shell' cavity is made of high-density, high-strength titanium that is precisely milled from a single block and meticulously hand-polished.

The FX17’s cable utilises three different transmission materials – gold, silver, and copper - in order to take advantage of the strengths offered by the different materials. The gold, silver and copper are forged at over 1000 degrees and undergo secondary refining to form crystalline monocrystals to remove impurities and reduce transmission loss. Each of the three elements has its own advantages, which together result in significantly improved sound quality.

Three audio plugs including USB-C

Included with the FX17 are three swappable audio plugs – 3.5mm single-ended, 4.4mm balanced and a Type-C connector with built-in digital decoding and DSP, allowing you to enjoy high-quality audio no matter the device you are connected to. The Type-C swappable plug features a built-in DSP audio decoding chip that supports up to 32Bit/384kHz high-resolution PCM. It also supports 8-band high-precision PEQ through FIIO's proprietary algorithm and the FIIO Control app or web interface, the PEQ allows you to adjust the headphones’ frequency response curve as first seen in the FiiO K19 headphone amplifier.