Fostex TH616

The Fostex TH616 is a semi-open audiophile headphone that marks the noteworthy return of the Japanese manufacturer to the high-end market. With its black walnut ear cups and 50 mm Biodyna diaphragm drivers, this wired circumaural model delivers a sound reproduction that combines smoothness and precision. Equipped with a powerful 1 Tesla magnetic motor and a meticulous design, the TH616 is aimed at audiophiles and sound professionals seeking precise, nuanced listening quality.

Refined Japanese design with impeccable finish

The TH616 features genuine black walnut ear cups, sculpted with particular attention to detail. The openings on the cups are inspired by sunbeams dancing through the depths of the forest, creating a distinctive pattern that evokes traditional Japanese aesthetics. This semi-open design not only enhances the visual appeal of the headphone, but also plays a crucial role in its sonic signature, enabling better spatialization and a more airy soundstage.

The structure of the headphone is built around a robust headband whose curvature naturally follows the shape of the skull. All structural parts and joints are made of metal, ensuring durability and stability while keeping the weight remarkably low at 370 grams. The vertical and horizontal swivel mechanisms of the ear cups, along with the wide height adjustment range (nearly 3.5 cm on each side), allow for an optimal fit on virtually any head shape.

Cutting-edge audio technology by Fostex

At the heart of the TH616 are 50 mm electrodynamic drivers using proprietary Biodyna technology. These bio-cellulose fiber diaphragms, a field of expertise for Foster Electric (Fostex’s parent company), offer an optimal stiffness-to-weight ratio. The absence of a traditional peripheral suspension on these diaphragms contributes to more faithful reproduction of bass and midrange frequencies, particularly in passages with high amplitude.

The magnetic circuit delivers an impressive power of 1 Tesla, ensuring an extended dynamic range with minimal distortion. This configuration enables the TH616 to reproduce an exceptionally wide frequency range, spanning from 5 Hz to 45 kHz.

The detachable connectors on the headphone are rhodium-plated for enhanced resistance to wear and corrosion, thus increasing their long-term reliability. The supplied Y-type cable uses high-performance HiFC copper, specially treated to provide optimal conductivity and precise transmission across the entire audible spectrum.

A balanced and refined sound signature

The TH616 stands out for its spacious and deep sound reproduction, skillfully combining smoothness and precision. Its harmonious sound signature avoids the pitfalls of overly analytical headphones while still delivering a remarkable level of detail. The bass is deep and well-defined, the mids are natural and present, while the highs are silky and extended.

Thanks to its semi-open design, the TH616 offers a spacious, airy soundstage with excellent instrument separation. This makes it a valuable tool for critical listening sessions or studio work, where fine detail perception is essential.

Versatility is one of its major strengths: it does not favor any particular musical genre, proving equally comfortable with complex classical orchestrations, contemporary electronic productions, or rock. While the TH616 reveals its full potential when paired with quality electronics, such as the SPL Phonitor xe headphone amplifier used during testing, it remains remarkably forgiving with more modest sources.

Comparison with other models in the range

The TH616 positions itself as the entry model in Fostex’s premium range, below the higher-end TH808. While the latter shares many features with the TH616, it benefits from significant improvements such as a more powerful magnetic circuit (1.5 Tesla versus 1 Tesla) and specially designed dual-layer metal grills to reduce resonances.

Nevertheless, the TH616 represents a notable evolution compared to previous generations of Fostex headphones, with a refined Biodyna diaphragm and optimized damping. It follows in the footsteps of the brand’s iconic models such as the TH900mk2 or the TH909, from which it inherits the overall architecture while offering its own distinct sonic signature.

Remarkable versatility for audiophiles and professionals

Although primarily designed for audiophiles, the TH616 also proves to be an excellent tool for sound professionals. Its precision and neutrality make it an ideal candidate for studio monitoring, while avoiding the trap of a clinical or fatiguing sound.

With a sensitivity of 96 dB/mW and a maximum input power of 1800 mW, it offers an impressive dynamic range, capable of faithfully reproducing the most subtle nuances as well as the most intense passages. These characteristics, combined with its robust construction, make it a reliable companion for extended recording or mixing sessions.

The TH616 comes with a detachable Y cable featuring rhodium-plated dual-pin connectors and a gold-plated 6.35 mm jack, as well as a storage pouch. For users wishing to explore the possibilities of a balanced connection, Fostex offers the optional balanced cable ET-H3.0N7BL (sold separately).

Technical Specifications

Main Technical Specifications

• Type: Open-back dynamic
• Impedance: 25 Ω
• Sensitivity: 96 dB/mW
• Maximum input power: 1,800 mW
• Frequency response: 5 – 45,000 Hz
• Weight: approximately 370 g (excluding cable)

Transducer Technology

• 50 mm BioDyna diaphragm transducer
  • Made from ultra-fine bio-cellulose fibers combined with other optimized materials
  • Delivers high resolution, smooth mid-high frequencies, and deep bass
  • Free-edge diaphragm design ensures faithful reproduction of bass and mid frequencies
• Ultra-powerful magnetic circuit
  • Magnetic flux density of 1 Tesla for low distortion and wide dynamic range
  • Neodymium magnet for superior acoustic performance

Design and Materials

• Open-back housing in solid black walnut
  • Lightweight yet rigid design minimizes unwanted resonances and vibrations
  • Unique opening sizes eliminate resonances at specific frequencies for clearer sound
• High-quality lightweight mechanical components
  • Aluminum frame for durability and weight reduction
  • High-density resin baffle plate minimizes resonance noise and enhances sound clarity

Connectivity and Cables

• Detachable 2-pin rhodium-plated connectors
  • High hardness, abrasion, and corrosion resistance for increased reliability
  • Compatible with the balanced ET-H3.0N7BL cable (sold separately) for balanced connection
• High-performance pure copper cable
  • Uses high-quality HiFC copper for excellent conductivity and clear sound across all frequencies
  • 3 m Y-cable with 6.3 mm gold-plated stereo plug

Comfort and Ergonomics

• Premium faux leather ear pads
  • Low-resilience cushion for extended listening comfort
  • Provides high acoustic isolation for an immersive audio experience

Included Accessories

• Cable: 3 m detachable Y-cable (2-pin rhodium-plated connector, gold-plated base)
• Additional accessories: leather pouch, instruction manual, and warranty card

Limited Edition and Manufacturing

• Made in Japan to commemorate Fostex’s 50th anniversary
• Designed in solid black walnut, a high-quality natural wood, with a unique open-back design
• Inspired by traditional Japanese woodworking and sunlight filtering through trees
• Hand-assembled in Japan for premium quality and craftsmanship
• Winner of the VGP 2024 Winter Gold Award