Fosi Audio IM4 black
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.
Open
Construction
3.5 mm
Connection type
Without microphone
Microphone design
20-20 000 Hz
Frequency range
Key features of the Fosi Audio IM4 headphones, black
- Open design for a more airy and natural sound
- The Fosi Audio IM4 headphones have a 10mm dynamic transducer with a beryllium-coated diaphragm
- Dual magnet N52 and dual acoustic chamber
- Frequency range 20 Hz - 20 kHz
- Sensitivity 109 dB and impedance 21 Ohm
- Lightweight design 7g per earpiece
- Removable 2-pin 0.78 mm cable
- Includes 3.5mm gold-plated jack connector
- Interchangeable sound nozzles (brass and aluminium)
- Three types of earbuds for sound customization
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.
Technical specifications
- The inverter: 10 mm dynamic, N52 dual magnet
- Membrane: PU with beryllium coating
- Frequency range: 20 Hz - 20 kHz
- Sensitivity: 109 dB/mW
- Impedance: 21 Ohm
- Body Material: CNC aluminium alloy 6063
- Cable connector: 2-PIN 0.78 mm
- Audio connector: 3.5 mm gold-plated jack
- Cable: 4-core, 392 fibers 5N OFC silver-coated copper
- The cable length: 1,3 m
- Weight of one hearing aid: 7 g ± 0,5 g
- Weight with cable: 38 g ±1 g
- Colour: black
Package contents
- Fosi Audio IM4 headphones
- 3.5 mm cable
- Carrying case
- User manual
- Quick instructions
- Brass nozzle
- Balanced earpieces
- Bass earpieces
- Deep Bass Earmuffs
Impedance
This indicates how power-hungry the headphones are. Headphones with lower impedance (e.g. 32 Ω) are ideal for mobile phones and laptops. Higher impedance (e.g. 80 Ω and above) is more suitable for Hi-Fi players and amplifiers. Frequency range
Indicates what sounds the headphones can play. The normal range is 20 Hz - 20 kHz, which corresponds to what the human ear hears. Lower Hz = deeper bass, higher kHz = more detailed treble.Specifications
Type of headphones
Connection
Features and functions
Headphone characteristics
Microphone characteristics
Colour
Weight
Backlight
Number of headphones
Charging // EU Directive
Packaging
Perfect Sound Group s. r. o. | Čerčanská 640/30 | 140 00 | Praha 4 Krč | [email protected] | +420 722 702 122
Specifications can be changed without notice. Images are for illustrative purposes only.
