FiiO 2026: A Preview of In-Ear Monitors (IEMs) and Flathead Earbuds

FiiO will launch new in-ear monitors (IEMs) and flathead earbuds in 2026, although the company’s primary focus is clearly on over-ear headphones, as previously reported by Hi-Fi Hub. According to FiiO’s CEO, James Chung, the company did not release any IEMs or flathead earbuds with significant market impact in 2025, and some planned models were ultimately delayed. Below is an overview of the new products expected in this category for the coming year.

Which IEMs and flathead earbuds will be launched in 2026?

FiiO plans to introduce two IEMs: a dynamic-driver model called OAK NANO and a hybrid model named FX25. There will also be the release of a flathead earbud featuring ear hooks, designed to route the cable over the ears, called FF15, which will be offered in two different sound-tuning versions.

Finally, a model whose final form factor has not yet been confirmed, whether IEM or flathead, was revealed under the name Luming Vocal Special Edition, developed in collaboration with audio enthusiasts.

Snowsky OAK NANO In-Ear Monitor (IEM)

The successor to the FiiO FD7, the OAK NANO is a single dynamic-driver IEM that employs a diaphragm made from a beryllium metal alloy. According to James, its original designation was FD17; however, the company ultimately decided to integrate it into the OAK headphone line, which appears to be exclusive to the Snowsky sub-brand.

For context, the FD7 was launched in 2021 and featured a dynamic driver with a pure beryllium diaphragm, a material known for delivering high dynamics and fast transient response, as well as low distortion, due to its low density and high elasticity.

The primary challenge associated with the FD7 was the limited supply of pure beryllium diaphragms. According to James, only a single manufacturer in the United States was producing them, and lead times were excessively long, forcing FiiO to discontinue the FD7. As a result, the company opted to use a beryllium alloy diaphragm in the OAK NANO rather than pure beryllium.

James emphasized that the OAK NANO diaphragm is not beryllium-coated. Instead, beryllium is incorporated into a compound mixture to form a metal alloy. According to the founder of FiiO, the characteristics of this new diaphragm closely approximate those of pure beryllium.

The OAK NANO housing is made of a titanium alloy, and its shape has been optimized to improve comfort compared with the FD7. James also noted that FiiO spent approximately four years refining all aspects of the IEM’s development.

The OAK NANO is scheduled for release in May 2026.

FiiO FX25 In-Ear Monitor (IEM)

The FX25, successor to the FX15, introduces improvements based on the audience’s preference for a fuller sound, according to James. To achieve this, a dedicated balanced armature (BA) driver for the midrange was added. As a result, the frequency allocation among the BA drivers and electrostatic (EST) drivers has been revised compared with the previous model.

In the FX15, there was only one BA driver responsible for both the midrange (500 Hz to 2 kHz) and lower treble (3 kHz to 6 kHz), operating alongside one dynamic driver (DD) for bass frequencies and four electrostatic (EST) drivers for upper mids (6 kHz to 12 kHz) and high treble (above 12 kHz).

In the FX25, the configuration consists of one BA driver dedicated to the midrange, one BA driver for the treble region (lower treble and upper mids), four EST drivers for the ultra-high frequencies (above 12 kHz), and one dynamic driver handling the low frequencies (sub-bass, bass, and mid-bass).

According to James, the FX15 configuration resulted in a “leaner” sound that was better suited to instrumental string music. In contrast, the FX25 is designed to be more aligned with the preferences of listeners who favor vocals and pop music.

The FX25 housing is made from fiber material, which offers “high strength and low weight,” according to James. He also noted that IEMs made from 3D-printed resin are more prone to cracking compared with fiber-based constructions.

The FiiO FX25 is expected to be released in July 2026.

FiiO FF15 Flathead Earbud

Unlike the traditional flathead earbud design, the FiiO FF15 incorporates ear hooks that route the cable over the ears. According to James, this hook-based design improves stability and fit, as one of the main challenges of flathead earbuds in general is securing the housing within the user’s ear concha.

Another notable aspect of the FF15 is that it will be available in two versions with different sound tunings. According to James, one version will feature a tuning oriented toward “classic pop,” while the other will adopt a “modern tuning” focused on higher resolution.

The FiiO FF15 is scheduled for release in July 2026.

Luming Vocal Special Edition

Developed in collaboration with audio enthusiasts, the Luming Vocal Special Edition is described by James as an “experimental project” by FiiO. The manufacturer’s goal was to create a headphone with a highly distinctive sound, specifically tailored to pop music from Hong Kong and Taiwan from the 1980s and 1990s.

According to James, the Luming represents a strategic bet for FiiO, as its development followed an “extremely targeted” approach. He explained that the intention is to attempt to “open a new path in the current headphone market,” which is why “no commercial targets were established for this model.” If this approach proves successful, the company plans to develop additional special editions with different sound signatures.

The Luming Vocal Special Edition is expected to be released in May 2026.