Discover detailed, spacious sound with the Fosi Audio i5, a full-size open-back planar magnetic headphone engineered for high-resolution listening. Combining a large 97mm planar driver, precision magnetic control, natural materials, and an ergonomic design, the i5 is built for listeners who want an expansive and highly detailed presentation.

At the heart of the i5 is a 97mm planar magnetic diaphragm measuring just 2μm thick. Its magnetron-sputtered silver alloy coating is designed to provide fast, accurate diaphragm response and detailed sound reproduction, while 44 N50 neodymium magnets provide precise magnetic control. The result is a low-distortion presentation with fast transients and high levels of detail across the frequency range.

The open-back architecture allows sound to develop naturally around the listener, creating an expansive and holographic soundstage. An acoustically transparent grille helps reduce resonance while maintaining the open character of the design, making the i5 particularly suited to critical listening, high-resolution music, acoustic recordings, classical music, gaming, and other applications where spatial presentation matters.

The i5 is built around a handcrafted walnut acoustic chamber and CNC-machined aluminum frame, giving it a distinctive combination of natural materials and modern precision engineering. A genuine sheepskin headband and breathable protein-leather ear pads provide a comfortable fit, while the memory-steel headband, multi-axis earcup pivots, and silicone adjustment sliders allow the headphone to adapt to different head shapes and listening positions.

With a 28Ω nominal impedance and 98dB/mW sensitivity, the i5 is relatively easy to drive compared with many high-end planar headphones, although Fosi Audio recommends an amplifier capable of at least 500mW for optimal performance.

Key Features:

Open-back planar magnetic headphone design
Large 97mm planar magnetic driver
Ultra-thin 2μm diaphragm
Magnetron-sputtered silver alloy diaphragm coating
44 N50 neodymium magnets
10Hz–50kHz frequency response
Less than 1% THD at 100dBSPL
98dB/mW sensitivity at 1kHz
28Ω nominal impedance
Recommended amplifier power of 500mW or more
Handcrafted walnut acoustic chambers
CNC-machined aluminum frame
Genuine sheepskin headband
Breathable protein-leather ear pads
Multi-axis pivoting earcups and adjustable silicone sliders
Acoustically transparent open-back grille

What's Included:

Fosi Audio i5 headphones
4.4mm cable
XLR adapter
User manual