Home » Reviews » Earphones » Earsonics ONYX Review – Expect the Unexpected

Earsonics ONYX Review – Expect the Unexpected

Pros –

Class-leading build quality, Nicely balanced W-shaped signature, Awesome bass power and control, Very spacious stage, Very Easy to drive

Cons –

Treble resolving power just average in-class

Verdict –

Ergonomics and build perform at the highest level and its sound is engaging yet tasteful, retaining overall balance. It is my pleasure to recommend the ONYX for those wanting an engaging midrange IEM.

Introduction –

Earsonics is a French audio brand who has achieved a solid international presence with their high-end IEMs. The company initially made waves with their all-BA reference monitors and have since tried their hand at hybrid designs that came alongside new metal shells. The ONYX is their latest project which finally sees the light after having been teased for quite some weeks. This model seeks to fill-out their product lineup with a more affordable option. In fact, the company was so dedicated to value that they are only offering this IEM directly to consumers rather than by distributors to cut out middle-man costs. The result is an IEM that implements technologies and specifications seen on their pricier models at a far more accessible price point.

The ONYX just launched for 590 EUR at the time of writing. You can read more about it and treat yourself to a unit directly from Earsonics here!

Disclaimer –

I would like to thank Thibault from Earsonics very much for his quick communication and for reaching out to organise a review of the ONYX. All words are my own and there is no monetary incentive for a positive review. Despite receiving the earphones free of cost, I will attempt to be as objective as possible in my evaluation.

Contents –

Specifications –

  • Driver: 1x DD, 2x BA mid, 1x BA high
  • Impedance: 16.5 ohms
  • Sensitivity: 122 dB
  • Frequency Response: 10 Hz – 20 kHz

Behind the Design –

Hybrid Drivers

Like many modern high-end IEMs, the ONYX uses a hybrid driver setup with a single DD woofer, 2x BA mids and 1x BA treble. The company is using HQ low-variance discrete components alongside proprietary, impedance-matched drivers designed to their spec. The company also reasons that this makes the earphone easy to drive from a variety of sources.

Acrylic Heart

At the core of the ONYX is the acrylic heart which is a 3D acrylic acoustic chamber. It provides support for the drivers in addition to reducing resonances. Specific positioning of each transducer to provides phase coherence alongside the company’s desired frequency response via a 3-way passive crossover.


The output nozzle of the earphone implements a specifically designed bell and tuning resonator that corrects the frequency response following the acrylic heart chamber. It serves to further optimise phase coherence and reduce resonances that may harm high-frequency extension.

Unboxing –

The earphones come in a handsome black box with a soft-touch finish and “ONYX” branding in gloss film. Opening the magnetic latch reveals the IEMs within protective foam inlets with a standard zipper carrying case below. To the side is a separate compartment containing the accessories. Out of the box, Earsonics provides 2 pairs of silicone ear tips, 2 pairs of Comply foam ear tips and 2 pairs of dual-flange tips. In addition, the ONYX comes with a cleaning tool and paperwork for authenticity.  

Design –

Earsonics’ recent shell designs have been a beautiful display of metalwork and the ONYX is no different. These earphones employ shapely all-metal 2 piece shells with an almost Daft Punk-esque aesthetic. The texture tells me these are injection moulded rather than CNC shells giving them an awesome satin finish. Despite this, the tolerances are excellent with nigh-perfect faceplate matching and smooth, well-finished edges all around. The ONYX is an earphone to be enjoyed both in and out of the ear with craftsmanship that is best appreciated close-up.

Above, users will find the widely adopted 0.78mm 2-pin removable cable interface. The stock cable offers sound quality, a 4-core unit with a braided design and soft, transparent insulation. It sports 4C-HR silver conductors. It is rather thin and a little rubbery, but still offers sound ergonomics and minimal microphonic noise transmission. The metal connectors provide contrast to the dark housings and the pre-moulded ear guides offer a comfortable and stable fit for my ears. Earsonics also offer an upgrade cable at an additional cost of 199 EUR.

Fit & Isolation –

From visual inspection, I wasn’t sure what to expect from the fit as Earsonics’ IEMs are one of the more unorthodox silhouettes on the market. Colour me impressed for the ONYX provides excellent comfort and stability on behalf of their shapely and well-contoured design. I was able to wear them for hours at a time without discomfort or hotspot formation. Though the shells are slightly larger than average, those with average-sized ears should have no difficulties. Their ergonomic shaping helps to achieve excellent articular fit with the concha, aiding stability and minimising hotspot formation.

The well-angled nozzles also contribute as they position the housings flusher with the outer ear contributing to an impressively low-profile fit despite the width of the shells. The well-angled and slimmer nozzles produce a slightly shallower than average fit depth. In addition to their vented design, wearing pressure is kept to a minimum. In addition, isolation is above average and easily suitable for daily commute whilst permitting some spatial awareness. It should be noted that some driver flex is apparent despite their vented design, however, I did not find this to affect reliable function or performance during my testing. Those wanting the best isolation for especially noisy environments may still want to investigate a fully-sealed option that said.

Next Page: Sound Breakdown



Ryan Soo

Ryan Soo

Avid writer, passionate photographer and sleep-deprived medical student, Ryan has an ongoing desire to bring quality products to the regular reader.


One Response

  1. Bonjour,
    Je suis bien impressionné par votre essai. Il correspond presque à la revue parfaite que je rêvais de lire sur un IEM !
    Souvent je relève des courbes pour compenser tel ou tel de mes iem. Par exemple les aiguës sur mon Oracle ou sur le Tri i3, ou encore le Final F4100. Les extrêmes basses sur le S12. Etc .. Mais rarement je laisse le naturel, parce que j’aime la coloration, naturellement sans exagérer. Il n’y a que cet étonnant et méconnu Senfer MT100 Pro qui a “mon” équilibre. D’ailleurs je ne le trouve aucune Review. Ce qui est trop plat est insatisfaisant ou frustrant, car la vie musicale n’est jamais ainsi.
    Ce qui est impossible à régler est la scène, l’espace. Je crois que le Mest MKII est l’un des fleurons à ce titre. J’hésite à le prendre, car son medium inférieur est un peu mince d’après beaucoup d’études.
    2 questions s’il vous plaît :
    Ce Onyx a une belle scène sonore, diriez vous qu’elle est aussi bonne que sur le Mest mkii ?
    Les aiguës sont ils un peu relevables, pour améliorer la finesse, sans le rendre dur ? (J’ai 60 ans, je perds des aiguës)
    Merci infiniment pour votre travail que j’apprécie beaucoup.
    Amitiés Olivier

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