Fosi Audio IM4 black

The Fosi Audio IM4 headphones in a sleek black design are open in-ear monitors designed for listeners who want a compact earbud format but also require an airy, surround sound experience. The open design helps reduce pressure in the ears and creates a wider, more natural soundstage more typical of large open-back headphones. Thanks to their precise tuning, they are suitable for long-term listening without fatigue, whether at home, when travelling or at work. Reproduction is handled by a 10mm dynamic transducer with beryllium-coated diaphragm and dual N52 magnet system. The combination of dual chamber and acoustic damping delivers a balanced, detailed and controlled sound with tight bass, natural mids and clean highs without aggression. Removable 2-pin cable allows for easy replacement or upgrade according to user preference.

Hi-Fi sound with dual magnetic system

The Fosi Audio IM4 headphones use a 10mm dynamic transducer with dual N52 magnets to ensure precise control of diaphragm movement. Beryllium-coated diaphragm improves stiffness and response speed. The double acoustic chamber helps balance pressure and optimise bass response. The result is a wide soundstage with clear details and low distortion. The sound is balanced and suitable even for demanding audiophiles.

Comfort and ergonomics for everyday use

Each earpiece weighs approximately 7 grams, ensuring high comfort even when worn for extended periods. Ergonomically shaped aluminium bodies are made by CNC machining from 6063 aluminium alloy. The surface is smooth, pleasant to the touch and hypoallergenic. The open design reduces the feeling of being closed in the ears. Thanks to their light weight, they are also suitable for listening for several hours.

Customizable sound and quality workmanship

Three types of earcups - Balanced, Bass and Deep Bass - are included to adjust the sound character. Interchangeable brass and aluminium sound nozzles allow fine tuning of treble and bass. The cable is a 4-conductor, 392 strand 5N OFC silver-coated copper cable, which ensures quality signal transmission. The removable 2-pin connector makes it easy to upgrade the cable to a symmetrical variant, for example. The combination of aluminium construction and a distinctive metal grille gives the IM4 a modern and premium look.