Self-calibrating professional headphones

The Hefio One headphones give you the perfect sound reproduction that adjusts the frequency response to user’s individual ear with our own calibration algorithm. The headphone design combines separate tweeter and woofer elements with gentle ear insertion that produce the full spectrum with comfort and quality.

Headphones audiophiles love

Clearest sound on the market

Better distinction of different musical instruments

Superior clarity of speech

Same sound every time you use the headphones

Equal reproduction of the whole frequency spectrum, without distortions

A complete frequency range in a very compact size

Less feeling of sound coming inside your head

Better spatial perception, ideal for 3D gaming

Features audio professionals need

Superior flat response playback for reference headphone use

Playback that is always the same for every listener, independent of anatomy or headphone positioning

Accurate control over the sound reproduction with target responses of your choice
More choices with Premium software

Design that minimizes occlusion effect with gentle ear insertion, without sacrificing sound quality

Truly accurate sound spatialization, independent of variations in headphones and ears

Access the reproduced sound for further analysis
Premium software feature


Hefio headphones sound great even without self-calibration and they work without any additional software. Personalization requires Hefio software, which is free for Hefio headphones owners.

Hefio Calibrator

Personalization is carried out by using a mobile application, which runs on iOS, Android and Windows Phone devices. The result of the analysis parametrizes our high quality EQ algorithms, which optimize the listening experience for each individual user.

Hefio Player

In addition to Calibrator functionality, Hefio Player supports content streaming from Spotify, device media and online radio stations. These streams are processed with our EQ algorithm for optimal sound quality through the calibrated Hefio headphones. Two EQ target selections allow flat and natural audio enhancement profiles.

Hefio PersonalEQ

Hefio PersonalEQ is an application, which runs on OSX and Windows platforms, and enhances the output of any application that sends its audio to the default audio output of the device. These include – but are not limited to – media players, audio and video streaming service clients, web browsers and games. The users may further configure PersonalEQ according to their taste: flat and natural audio enhancement profiles and an additional 31-band user EQ enable further customization. Premium users may even choose between biquad and convolution based EQ implementations.

Technical details


Dual Dynamic Driver (Tweeter + Woofer)


40 Ω


20 – 20000 Hz


3.5 mm TRRS, gold plated