Fosi Audio i5 Open-Back Planar Magnetic Headphones

Immersive Planar Sound. Exceptional Detail. Refined Craftsmanship.

The Fosi Audio i5 is an open-back planar magnetic headphone designed for listeners who want high-resolution sound, low distortion and an expansive, natural soundstage.

Featuring a large 97mm planar magnetic driver, ultra-thin diaphragm and precision magnetic system, the i5 delivers fast response, detailed reproduction and an immersive listening experience. Its combination of walnut wood, CNC-machined aluminum and premium materials creates a distinctive balance of performance, comfort and craftsmanship.

97mm Ultra-Large Planar Magnetic Driver

Big driver. Exceptional detail.

At the heart of the i5 is a 97mm planar magnetic driver with an ultra-thin 2μm diaphragm.

The large diaphragm is designed to provide fast response and improved detail retrieval, while a magnetron-sputtered silver alloy coating enhances conductivity for consistent audio performance.

Precision Magnetic Control

Fast, accurate and controlled.

Each driver uses a symmetrical magnetic system featuring 44 N50 neodymium magnets. The high-strength magnetic array provides precise diaphragm control for quick transient response and low distortion.

Combined with the planar magnetic driver, the i5 delivers detailed and accurate sound across your music collection.

Open-Back Design

A spacious, natural soundstage.

The i5's acoustically transparent open-back grille allows air to move freely around the driver, helping minimise resonance and creating a more open and expansive presentation.

The result is an immersive soundstage with greater spatial detail, making the i5 ideal for critical listening, music appreciation and high-quality home audio setups.

Refined Walnut & Aluminum Construction

Where craftsmanship meets performance.

The i5 combines handcrafted walnut wood chambers with a CNC-milled aluminum frame, creating a premium aesthetic with a distinctive natural character.

The genuine sheepskin headband and signature S-design accents complete the refined look, while the robust construction is designed for long-term use.

Designed for Long Listening Sessions

Comfort that stays with you.

The i5 features a memory-steel headband with multi-axis pivoting earcups that adapt to different head shapes.

A smooth silicone adjustment system allows precise positioning, while breathable protein leather earpads help improve comfort during extended listening sessions.

High-Resolution Audio Performance

The i5 delivers a frequency response of 10Hz–50kHz, with a nominal impedance of 28Ω and sensitivity of 98dB/mW @ 1kHz.

With a maximum SPL of ≥120dBSPL and recommended power of ≥500mW, the i5 is designed to perform at its best when paired with a suitable headphone amplifier or DAC/amp.

Why Choose the Fosi Audio i5?

• Open-back planar magnetic headphones
• Large 97mm planar magnetic driver
• Ultra-thin 2μm diaphragm
• Magnetron-sputtered silver alloy coating
• 44 N50 neodymium magnets per driver
• Expansive and immersive open-back soundstage
• Low-distortion, high-resolution audio reproduction
• Handcrafted walnut wood chambers
• CNC-milled aluminum frame
• Genuine sheepskin headband
• Memory-steel headband
• Multi-axis pivoting earcups
• Silicone adjustment system
• Breathable protein leather earpads
• 10Hz–50kHz frequency response
• 28Ω nominal impedance
• 98dB/mW sensitivity @ 1kHz
• Maximum SPL ≥120dBSPL
• Recommended power ≥500mW
• Includes 3.5mm cable and 6.35mm adapter

Specifications

What's in the Box

• Fosi Audio i5 Headphones
• 3.5mm Cable
• 6.35mm Adapter
• User Manual