Earsonics ONYX Review
Copyright Earsonics 2022

Earsonics ONYX Review

In our review today we look at the new Earsonics ONYX which is a hybrid single dynamic and triple BA in-ear monitor. It is priced at €590.

Disclaimer: This was sent to us as a sample for our honest opinion. Headfonics is an independent website with no affiliate links or services. We thank the team at Earsonics for giving us this opportunity.

To read more about Earsonics products that were previously featured on Headfonics click here.

Note, that this article follows our latest scoring guidelines which you can read up on here.

Earsonics ONYX Review
Earsonics ONYX Review
The Earsonics ONYX successfully fills the gap for Earsonics metallic lineup and is perfect for those who want to experience the immersive tuning STARK offers but are reluctant to carry a powerful DAP around.
Slide here to add your score on the gear!60 Votes
Energetic bass
Good frequency extension on either end
Expansive staging
No balanced cable
Slightly recessed mids
Needs good power for the treble to shine
Reader's Score

The boutique French audio brand Earsonics garnished their full metallic design with a stealthy, satin finish and put together the ONYX. This is their 4th IEM of the metallic series with a 3-way, 4-driver design bearing their Technologie Hybride® hallmark and “Acrylic Heart” infrastructure.

This is the most mysterious in-ear yet from Earsonics, with a lot of resemblance in design to the TOTL hybrid model STARK, but it is much more sensitive so it can be powered by weaker sources than its flagship sibling.

Earsonics ONYX Review
Copyright Earsonics 2022

Tech Highlights

The Earsonics ONYX Hybrid IEM has a triple Balanced Armature and a single dynamic driver configuration. The dynamic driver is responsible for the lows, and the hybrid crossover assigns 2 BA for the mids and 1BA for the treble frequencies.

According to Earsonics, when designing the ONYX, the leitmotif of the team is to use the finest materials, that’s why the same latest generation 3D acrylic core used on the flagship IEM Grace Platinum, is employed on the OYNX aside from the nearly metallic identical housing design on the STARK and the BLADE.

The design combines also their state-of-the-art Acrylic Heart® Technology – phase alignment measures for coherent sound plus their Truewave® Technology – cannula with a 3D resonator which is a part of the tuning design.

Earsonics ONYX Review


The ONYX is true to its name, stealthy in design and the whole body has a smooth dark finish. It shares the same aesthetics as the STARK, the BLADE, and the CORSA, consisting of a vented, metallic body and a high relief, 3D faceplate design that displays Earsonics’ logo along techy contour lines.

The silver-colored cable has a high contrast visual compared to the bodywork, and you can see beautiful sheens bouncing off the body when lights hit it at different angles.

Earsonics ONYX Review

Comfort & Isolation

Despite using a full metallic design, the ONYX is quite compact in size and it sits well on the outer ear. The weight is spread evenly so there is no stress to the ears after a few hours of listening.

Passive sound cancellation, or isolation, on the other hand, is decent with a rather extended nozzle and thick silicone flanges. For even better comfort you may use the foams supplied, which will further enhance passive noise cancellation.


The ONYX comes with 3 sets of tips including memory foams, double flanges in M/L sizes as well as the common tips in 3 sizes.

As mentioned above, the insertion is quite deep and with the foams, you will get the most soothing and elaborative mid-lows, while the double flanges would offer the best isolation and help the IEMs sound cleaner and textured.

Earsonics ONYX Review

Stock Cable

The stock cable on the ONYX should be identical to the 4C Hi-Res cable on the CORSA and the STARK.

The soft braided cable offers great durability and a clean tone which has good synergy with the IEM. If you want to bring up even more bass or enhance the overall quality, it is easy to roll different cables as the ONYX uses standard 2-pin configurations.

The cable is very soft so there is no microphonics detected, and I prefer tightening the cables with the slider to the back of the neck for the best comfort.

Earsonics ONYX Review

Packaging & Accessories

You can never be disappointed with Earsonics’ packaging. The French company has some good attention to the experience and with the earphones, there is a certificate – with the crafter’s name and the birthday of the IEM on top.

Sound Impressions


As the hybrid design is consist of a dynamic driver the ONYX is given a full week of run-in before impressions are made. 

In general, the ONYX is a sensitive and well-extended IEM with a good hint of warmth in the mid-lows that pushes its dynamic performance. I am classifying it as an “M-shaped” tuning where a bump in the upper mids brings forward more clarity in the vocal, and the frequencies behind are smoothly delivered. 

With most pairings, the ONYX displays good balance, and it is colored vividly with the added intimacy and energy in the bass. The sensitivity also allows it to sound very punchy and dynamic even on smaller outputs like my laptop and small DAC dongles. It works well with streaming content that sometimes boosts the mid-bass and upper mids for dynamics and clarity.


The sub-bass roll-off gently and the ONYX is free from congestion. The dynamic driver sends plenty of punch down to 200Hz and with an elaborative decay with bass pitching instruments pushed to the stage front. The mid-bass that follows, is smooth and clean, which reminds me of the CORSA but on the ONYX it is more defined and full-bodied.

The tuning favors some instruments like cajons where the solid impact is loyally captured and resonances from the snare wires are clearly delivered. Acoustic instruments, in a similar way, have a satisfactory level of body and air, also displaying good intensity when strings are plucked.

The bass is responsive with a clean attack and elaborative in decay on different gears I pair the ONYX with, including the Shanling M3X, my laptop as well as Questyle’s M12 dongle. While the ONYX is quite sensitive and easy to get loud, there is good control and balance in its bass.


The bass has decent power and transitions smoothly into the mids which have a good level of clarity. The tuning has the thickness of the midrange frequencies carefully balanced such that the vocal line sounds unaltered and has just the right amount of weight and thickness to sound full and to sound distinctly positioned from the other backing instruments.

The upper mids are brought more forwarded and you can hear good intensity with harmonics, at the same time percussion instruments are very well defined and without any harshness. That renders an immersive headroom for music from ones like Cigarette After Sex, Daft Punk, etc that have a soothing voice and a smooth, melodious bass line.

Chord progressions, synthesized harmonics, and lighter vocalists in the upper mids region are swiftly presented with good control, also well weighted and rich in details. 


The higher register is on the timid side, which rounds off nicely some of the harsher instruments and presses down the sharpness of instruments like clarinets and flutes, as well as sopranos. A fair amount of air is still retained such that it doesn’t feel contained, though if you want exciting treble you may need to tune it up with an equalizer or by cable rolling.

In fact, I find the tuning very friendly for outdoor listening as it compensates for the ambient noise well and sounds quite clear and full in the lower register.

Though it doesn’t make cymbals and flutes sound very exciting, the rather extended and smooth treble works well for long listens, you can listen to it in the coffee shop, reading while sipping coffee for a few hours, and getting out with no fatigue.


With only 4 drivers the ONYX manages to sound moderately expansive. You can hear the midrange elements being positioned a few rows in front. No frequencies are overly boosted and the balance maintained helps render a complete and naturally presented stage that does not compromise the authenticity of the vocal.

Darker vocal or bass instrument imaging is softly rendered, probably due to the cross-over, especially on the higher gain when the responsiveness between the bass driver and BAs are more distinct. Despite that, lighter voices and percussion instruments are clearly defined with a sharper image.

Transients in higher pitches are well captured. You can easily picture where the instrument radiates from, and that helps define the soundstage rendered more realistically. With a dynamic driver handling the lows, strings plucking on double bass and big drums sound full and expansive and are presented quite intimately.

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