Fostex TH910 & TH919

Both models use a newly developed 50 mm BioDyna dynamic driver. Compared with earlier designs, Fostex has reworked elements such as the diaphragm edge in order to improve stability at different listening levels. According to the company, that should result in better-controlled, tighter bass that does not spill over into the rest of the range, while the suppression of unwanted resonances is intended to produce a smoother, more natural midrange and reduce any sense of haze. The idea behind these changes is to deliver a sound that is dense, clear and smooth, while still preserving scale and depth, so the listener hears more information without the presentation becoming overly analytical.

There have also been meaningful changes to the mechanical construction. Components such as the base plate and hanger are made from a lightweight magnesium alloy, which Fostex says reduces weight by around 20% compared with aluminium parts. The lighter structure, combined with revised ergonomics, is intended to improve comfort during long listening sessions. Rubber gaskets are used in the earcup swivel mechanism to reduce unwanted vibrations transferred from the housing to the listener's head and to make the moving parts feel quieter and more refined in use. The overall design aims to keep the headphones secure on the head without creating excessive clamping force.

The earcup housings are made from solid hard maple and finished using the traditional Japanese Urushi lacquer technique. This stage is handled by Sakamoto Otozo Shoten, a company founded in 1900. The 'foil pattern' finish uses black lacquer as the base, combined with hand-applied pieces of silver foil smoked with sulphur, creating a shimmering and deliberately irregular effect that gives both models a distinctly luxurious, almost collector-grade character. Fostex also notes that the combination of hard maple and hard lacquer is intended to avoid adding unwanted colouration, helping preserve solid, elastic bass and clean, well-extended treble without artificially emphasising any specific part of the spectrum.

The TH910 is the closed-back version for listeners who want to shut out the outside world and focus on the music. Its isolation is meant to make fine detail easier to hear and to reinforce a more intimate, precise presentation, which should appeal both to home listeners and to users working with sound. The TH919 takes a different route as an open-back model. Here Fostex uses an aluminium grille with a geometric pattern inspired by the Japanese woodworking art of Kumiko. The precise two-layer structure, built around a laser-cut mesh, has been tuned to reproduce a more natural and open sound field with high resolution while also helping to reduce listening fatigue during longer sessions, which is one of the defining strengths of a well-executed open design.

Both headphones use newly shaped ergonomic earpads made from dual-layer low-resilience memory foam, designed to conform more effectively to the listener's head and spread pressure more evenly. The headband and cushion are finished in natural sheepskin leather, and the supplied cable is a 2 m high-purity 7N OFC lead terminated with a 6.3 mm plug for conventional headphone outputs. For users with balanced sources, Fostex also offers an optional 4.4 mm cable as an additional accessory. The TH910 and TH919 are now available internationally, with widely cited pricing at around £2,659/$2,899/€3,299 for the TH910 and £2,899/$3,099/€3,499 for the TH919. Info and photos by Fostex.