Exceptional Transient Response

Pure Carbon Diaphragm

Widely used in aerospace and Formula 1, carbon fiber combines exceptional strength with low mass. Fosi Audio’s proprietary UTPT™ technology overcomes traditional thickness limitations, creating an ultra-thin carbon diaphragm with metal-like rigidity for faster transients and more accurate frequency response.

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UTPT™

Ultra Thin Ply Technology

Fosi Audio EU

Easy to Drive
Great Sound

Dual-Chamber Dynamic Driver

A low-distortion driver (THD ≤0.5% @1kHz) and precisely tuned dual-chamber design deliver a wide frequency response and spacious soundstage. Dedicated rear-chamber damping foam absorbs standing waves for cleaner sound.

Easy to Drive, Great Sound

With 37Ω impedance and 108dB sensitivity, Carbon 12 is easily driven by a dongle DAC or portable digital player, delivering high-quality sound wherever you go.

Warm, Full-Bodied Tuning

Carbon 12 delivers a natural, balanced sound with both accuracy and emotion. Fast transients and excellent detail meet slightly forward mids, creating rich, textured vocals ideal for pop and vocal-focused music.

Carbon Fiber Meets Titanium

The carbon fiber faceplate minimizes unwanted resonance between the housing and driver for cleaner sound. Crafted through layering, stamping, temperature control, forging, and CNC machining, each piece reveals a unique natural pattern.

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Dual-Chamber Construction

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The open front-chamber design relieves the pressure of IEMs, allowing sound to breathe for a spacious, natural soundstage and lasting listening comfort.

Dedicated acoustic damping foam in the rear chamber absorbs standing waves and unwanted reflections for cleaner, more natural sound. A diffused pressure-relief vent balances internal pressure for a more open soundstage.

Silver-Plated OFC Cable

Specially tuned for Carbon 12, the four-strand braided cable uses high-purity silver-plated oxygen-free copper for clean, low-resistance signal transmission that preserves every detail.

Explore More Sound Possibilities

Triple-tunable ear tips in three sizes adapt to your ear shape, letting you pick the bass response you like best.

Nozzle Tuning Foams

Includes low-, medium-, and high-density nozzle tuning foams, easily replaceable with the included tweezers. Higher density softens the upper treble, while lower density adds more brightness.

Product Specification

Driver 12mm Dynamic Driver with UTPT™ Thin-Ply Carbon Diaphragm

Housing Material TC4 Titanium Alloy with Carbon Fiber Faceplate

Frequency Response 20Hz–40kHz

Impedance 37Ω

Sensitivity 108dB/Vrms @1kHz

THD ≤0.5% @1kHz

Weight (Per Earbud) 7.5g

Cable 2-Pin 0.78mm Silver-Plated Oxygen-Free Copper Cable

Fosi Audio EU
  • 5 stars: 2 (67%)
  • 4 stars: 0 (0%)
  • 3 stars: 1 (33%)
  • 2 stars: 0 (0%)
  • 1 star: 0 (0%)
J
Joerg
Comfortable and balanced IEM for long listening

The Carbon 12 IEM are very comfortable to wear. The balanced sound fits very good to my preferred music (Progressive Rock, Pink Floyd). Their size fits even in small sized ears and the cable is soft and wraps perfect around my ears - so far the best IEM cable I used.
When you are ready to play a little bit with the attached damping foams and tips you will find a sound that suits to your expectation - except you are a bass junkie or prefer screaminf treble. The localisation of instruments and vocals is on a high level and should not disappoint. Just leave behind all the "funny" tuned IEMs and their sometimes extremely V-shaped tunes.

M
Mike Waite
Sounds great but doesn’t fit my ears.

Fosi ha a nice sounding product here, but the location and angle of the signal wires prevent those wires from going over my ears. I can’t be active and keep these in place. Someone need to review and reposition the location of the wires. If wire positioning were better, I’d give it five stars, it isn’t, and that’s why the low rating. If I loop the wire over my ears, the IEM pops out every time. This is the best positioning I could achieve.

A
Andrea Palese

È un IEM davvero fantastico: le membrane in carbonio restituiscono una separazione di tutti gli strumenti e voci notevole creando un effetto di sound stage davvero ampio.