Fosi Audio i5 Planar Magnetic Headphones

Fosi Audio i5 Planar Magnetic Headphones with 97mm Ultra-Large Diaphragms

Fosi Audio's i5 is a wonderfully built, comfortable headphone with fantastic resolution, excellent tuning, and a sound worthy of its planar moniker.

The i5 was born from Fosi Audio’s mission to make planar magnetic headphones more accessible - without compromising on sound quality, comfort, or design. Over a year of in-house development and acoustic tuning led to a headphone that delivers exceptional clarity, low distortion, and lifelike detail.

Crafted with an ultra-thin diaphragm using nano-level technology, an invisible high-powered magnetic system, and precision acoustic design, the i5 delivers high resolution and low distortion for a truly lifelike listening experience.

97mm Ultra-Large Diaphragm

The ultra-thin diaphragm, crafted with nano-level precision, delivers faster response, enhanced detail, and a more natural, clear, and layered sound.

Sputtered Coating Technology

Utilising advanced targeted sputtering technology, a highly conductive silver metal voice coil as thin as 1.3μm is precisely coated onto the diaphragm. This process significantly enhances sound refinement while ensuring durability, keeping excellent audio performance consistently stable over time.

Symmetrically Arranged High-Strength Magnetic Matrix

Each driver unit features 22 N50-grade neodymium magnets arranged symmetrically, ensuring precise and stable diaphragm vibration. This design enables accurate and swift dynamic response, effectively reducing nonlinear distortion to produce purer, more natural sound, faithfully reproducing the essence of music.

Rigid High-Transparency Acoustic Mesh

The high-transparency rigid rear mesh structure provides stable air pressure damping and linear feedback. It smooths out frequency spikes and reduces nonlinearity, achieving an open, airy soundstage with ultra-low acoustic resistance.

Ergonomic Design, Long-Lasting Comfort

Designed to follow the natural contours of the head, the i5 ensures a secure yet gentle fit. Even during extended listening sessions, it remains comfortable and pressure-free, letting you enjoy your music without distraction.

Dual-Axis Ear Cup Arms

The dual-axis ear cup arms allow seamless vertical and horizontal rotation for a custom fit to different head shapes, enhancing both comfort and stability.

Stepless Silicone Adjustment

The headband features a silicone adjustment slider with a damped, smooth feel, enabling easy and precise positioning based on personal preference.

Durable Memory Metal Headband

Made of high-strength memory metal, the headband maintains its shape over time. Lightweight and flexible, it reduces pressure and enhances comfort.

Breathable Skin-Friendly Earpads

Crafted with perforated leather and breathable fabric, the earpads stay cool and soft. Memory foam inside ensures all-day comfort without overheating.

Detachable Cable Design

The i5 features a detachable cable design with standard 3.5mm connectors on both sides, and is compatible with 3.5 mm and 4.4 mm headphone cables.

Refined Craftsmanship

Handcrafted walnut wood earcups are paired with a CNC-milled aluminium frame while genuine sheepskin headband and signature S-design accents exude understated luxury and timeless sophistication.

Our Review

The Fosi Audio i5 Planar Magnetic Headphones are a very tempting proposition for anyone who wants to step into high-end sound without the usual price shock. Built with care and packed with clever engineering, they manage to combine comfort, craftsmanship, and cutting-edge tech into one very impressive package. That ultra-thin 97mm diaphragm and finely tuned magnetic system work together to give you a sound that’s clear, detailed, and wonderfully lifelike, while the walnut wood earcups and genuine sheepskin headband make them feel as good as they look. Whether you’re settling in for a long listening session or just want to hear your music with more depth and realism than ever before, the i5 strikes a rare balance of performance, luxury, and everyday comfort.