Earsonics ONYX IEM Review






Earsonics ONYX IEM Review





Earsonics is a famous French company that was founded in 2005 by Franck Lopez and is specialized in the design and production of Custom (CIEM) and Universal (UIEM) In-Ear Monitors and gained a high popularity in the Audiophile community with products such like SM3, S-EM6, SM64, SEM-9, Velvet, Grace, Spark/Blade/Corsa and many more.

The ONYX is a project created by Earsonics with the goal to offer a High-End Universal IEM for an affordable price. It was therefore necessary to reduce distribution and processing costs as much as possible.

The ONYX is a Universal In-Ear Monitor that utilizes 3 BA + 1 DD Hybrid Driver configuration, which is a combination of 2xBA’s desiccated for the Midrange, 1xBA for the Treble area and a custom Dynamic Driver that is responsible for the Low’s. The ONYX comes also with some interesting features such like True Wave, Hybrid and Acrylic Heart Technology, which are integrated in to a fantastic looking Hand Assembled Exclusive Black Metal Shell.





I would like to thank Earsonics for providing the ONYX Universal IEM as review sample. I am not affiliated with Earsonics or any third person beyond this review and all these words reflect my true, unaltered opinions about the product.





Price & Availability:

The ONYX is a special project created by Earsonics to introduce a High-End Universal IEM for an affordable price, which is now available for 490,00 EUR. In order to achieve this price, Earsonics has set up a direct sales website for the ONYX without any intermediary. More information’s can be found under the link below;






Package and Accessories:

The ONYX came in a minimalistic black cardboard box with velvet like surface coating in black color that sports the ONYX branding on the top.

When you open up the top cover you will the Monitors and a zipper case that are carefully placed in to a foam sheet. At the right side of the foam layer is a compartment where you can access the accessories.


Inside the box are the following items;

  • 1 pair x Earsonics ONYX Universal In-Ear Monitors (UIEM)
  • 1 piece x UnHR 4C Silver cable with 0.78mm diameter 2-Pin connectors
  • 2 pairs x Bi-Flange Silicone Ear Tips
  • 2 pairs x Double Flange Silicone Ear Tips
  • 2 pairs x Foam Ear Tips
  • 1 piece x Zipper Case
  • 1 piece x Cleaning Tool
  • 1 piece x Print Material (Warranty Card, User Manual)


The Earsonics ONYX comes with three different types of ear tips. Included are 2 pairs of Bi-Flange Silicone Tips, Double Flange Silicone Tips and 2 pairs of Foam Ear Tips.

The zipper case is pretty small that ports the Earsonics (ES) branding on the top.






Features, Design and Build Quality:

The Earsonics ONYX is a solid looking Universal IEM that shares the same impressive design that we have seen on previous products the Spark, Blade and Corsa.

The ONYX features a Hand Assembled exclusive Mat Black metal shell “100% Made in France” that utilizes 3x Balanced Armature Drivers & 1x Custom Dynamic Driver that are carefully integrated in to the Acrylic Structure, which is the Heart of the ONYX, which is part of the Hybrid Driver Technology.

The heart made of acrylic is supported by a skeleton of the same material allowing it to beat at full speed while avoiding the problems associated with sound reverberation.

The faceplate of the ONYX sports the companies “ES” brand logo and looks wonderful.

At the inner surface of the main body are some artistic notches in form of waves; the slightly angled sound nozzles and a pretty small screw to fix the faceplate to the main body.

The sound nozzle has a smaller diameter compared to other products on the market.

The sound nozzle of the ONYX is equipped with Earsonics “True Wave Technology”, which is a special tube that allows an optimum work on phase control to archive a first-order “Magnitude” curve.

On the top of the monitors are the 0.78mm diameter 2-Pin female connectors that do offer a very tight and secure fit.

At the rear surface of each monitor are the second fixing screws and grid-shaped openings that give the ONYX the look of an expensive sports car, simply eye-catching!



Earsonics UnHR 4C Silver Cable:

The Earsonics ONYX comes with a 2-Pin cable that is made of 4Core high purity Silver Wire cable with a transparent insulation, which has a braided design.

The 0.78mm diameter 2-Pin male connectors do have a metal housing in silver color that do post both left and right markings and color indicators (red for the right connector).

Near the connectors are transparent heat shrink ear guides for a more comfortable over the ear wearing experience, which works pretty well especially on the go.

The cable features a transparent plastic chin slider and a metal Y-Splitter in the same silver color with the Earsonics branding on the top.

The 3.5mm Single Ended headphone jack has an L profiled metal housing with the same silver finish like the rest of the metal part and sports a transparent strain relief for extra durability.




Comfort and Isolation:

The Earsonics ONYX comes with the same Universal Monitor design like the Corsa (the Spark & Blade do share the same design), which all do have a fairly comfortable shape that fits perfectly in to my average sized ear concha’s. The passive noise isolation of the monitors is on an average level that is sufficient for the use in relative noisy environments like a metro, bus or train.




Drivability & Pairing:

The Earsonics ONYX is a very efficiently Universal In-Ear Monitor thanks to is pretty low impedance of 16.5 Ohms and a sensitivity of about 122dB, which makes it fairly ideal for the use with sources like Smartphone’s or Tablets that do have in general relative weak amplification capability.




Technical Specifications:

  • Driver Technology     : Hybrid Driver Technology
  • Driver Configuration   : 3 BA (2x Mid & 1x Treble) + 1 Dynamic Driver (Bass)
  • Freq. Resp.                 : 10 Hz – 20 kHz
  • Sensitivity                   : 122 dB/mW
  • Impedance                 : 16.5 Ohms
  • Connector                   : 0.78mm 2-Pin Connector





Equipment’s used for this review:

  • In Ear Monitors                    : Earsonics ONYX, Oriveti OH500, Dunu DK-4001
  • Sources (DAP/DAC)            : HiBy RS6, iBasso DX300, Lotoo PAW S1





Albums & Tracks used for this review:

  • Adele – My Little Love (Spotify)
  • Randy Crawford – On Day I Will Fly Away (Flac 16bit/44.1kHz)
  • Hayley Westenra – Odyssey Album (Dezzer HiFi)
  • Dionne Warwick – Walk On By (Flac 16bit/44.1kHz)
  • Sarah McLachlan – Angel (Flac 24bit/48kHz)
  • Sertap Erener – Aşk (Flac 16bit/44.1kHz)
  • Edith Piaf – Non Je Ne Regrette Rien (Flac 16bit/44.1kHz)
  • Diana Krall – So Wonderful (DSF)
  • Aretha Franklin – I Say A Little Payer (Flac 24bit/96kHz)
  • David Bowie – Heroes (Flac 24bit/192kHz)
  • Elton John – Rocket Man ((Flac 24bit/96kHz)
  • Barry White – Just The Way You Are (Flac 24bit/48kHz)
  • Isaac Hayes – Walk On By (Flac 16bit/44.1kHz)
  • Sting – Englishman in New York – (Flac 24bit/48kHz)
  • Eric Clapton – Wonderful Tonight (Flac 24bit/96kHz)
  • B.B. King – Riding With The King (Tidal Hi-Fi)
  • Dave Gahan – Kingdom (Tidal Hi-Fi)
  • U2 – Sunday Bloody Sunday (Flac 16bit/44.1kHz)
  • Bro Safari, UFO! – Drama (Deezer HiFi)
  • Armin Van Buuren – Vini Vici (Flac 16bit/44.1kHz)
  • Really Slow Motion – Deadwood (Deezer HiFi)
  • Jo Blankenburg – Meraki (Spotify)
  • Lorde – Royal (Flac 24bit/48kHz)
  • Toutant – Rebirth (Deezer HiFi)
  • Gogo Penguin – Raven (Flac 24bit/192kHz)
  • Portishead – It Could Be Sweet (Spotify)
  • Charly Antolini – Duwadjuwandadu (Flac 24bit/192kHz)
  • Michael Jackson – Billie Jean (Flac 24bit/192kHz)
  • Ferit Odman – Look, Stop & Listen (Flac 24bit/192kHz)
  • Chopin – Nocturn No. 20 In C-Sharp Minor (Flac 16bit/44.1kHz)
  • Fazıl Say – Nazım Oratoryosu (Live) (Flac 16bit/44.1kHz)
  • Vivaldi – Le QuarttroStagioni “The Four Season” (Deezer HiFi)
  • Otto Liebert& Luna Negra – The River (Flac 24bit/192kHz)
  • Lunatic Soul – The Passage (Flac 16bit/44.1kHz)
  • Deftones – My Own Summer (Shove it) (Flac 16bit/44.1kHz)
  • Photek – The Hiden Camera (Spotify)
  • Muse – Hysteria (Flac 24bit/48kHz)
  • Metallica – Sad but True (Flac 24bit/96kHz)
  • Opeth – Windowpane (Flac 16bit/44.1kHz)
  • Megadeth – Sweating Bullets (Tidal Hi-Fi)
  • Rush – YYZ (Flac 16bit/44.1kHz)
  • Rush – Leave That Thing Alone (Flac 16bit/44.1kHz)
  • Slayer – Angel of Death (Spotify)s
  • Liquid Tension Experiment 2 – Acid Rain (Spotify)
  • Yosi Horikawa – Bubbles (Spotify)






The Sound:

The ONYX shows Earsonics typical sound character that is mildly warm and lush in its tonality and highly rich and detailed in its presentation. The lower frequency region is punchy, fast and impressively controlled. The midrange on the other hand sounds quite lush, transparent and detailed, while the treble area are shown with a decent level of authority, sparkle and extension, especially for a non-ChiFi IEM at this price level.

The Earsonics ONYX review has been written after a burn-in period of approx. 70 hours. I have used the Stock Single Flange Silicone Ear tips and the UnHR 4C Silver cable that are included to the package.



The lower frequency region (bass) of the ONYX is produce with Earsonics custom Dynamic Driver that is part of the Hybrid Driver Technology. What I have immediately recognized was how well the powerful bass is isolated from the rest of the sounds spectrum, which means that it doesn’t affect the midrange and treble are in a negative manner.

The ONYX offers a solid subbass performance with a powerful, deep and well extending presentation. The ONYX shows a great sense of subbass depth, rumble and intensity when I do listen to string instruments such like the contrabass and bass guitar or with percussion instruments like kick drums, without to have any negative conditions in terms of clarity and resolution. The subbass depth and rumble of the ONYX sounds impressive when I do listen to songs like Massive Attack’s “Angle”, Lorde’s “Royals” and Armin Van Buuren’s “Vini Vici”.

The midbass region of the Earsonics ONYX stands out with its pretty tight, controlled and impactful presentation, which doesn’t show any negative situations such like a midbass hump, muddiness and mixings even in very fast and complex bass passages.

Instruments like cross drums and trumpets are quite accented and do show a warmish and soft tonality. The midbass performance of the ONYX is impressive from rock to pop, from classical music to electronic music. Moreover, I highly enjoyed the bass character of the Earsonics ONYX, which is reproduced in a pretty smooth, rich and full-bodied manner thanks to the well adjusted Dynic Driver.



The Earsonics ONYX shows a mildly warm midrange tonality and offers a very liquid, pretty smooth and lively character, while the sense of transparency and airiness is on an adequate level. The general midrange character can be described a nicely smooth almost velvet like in its presentation but without to sound veiled or dull.

The lower midrange of the Earsonics ONYX shows nice sense of depth, warmth and body when I do listen to vocals like Barry White or Isaac Hayes, which are reproduced in a pretty emotional and full bodied manner, without to show negative conditions such like muddiness. Female vocals on the other hand do sound quite detailed, musical and intimate thanks to the fairly highlighted but highly controlled upper midrange character that offers efficient sense of extension and detail retrieval, while listen to female voices such like Adel, Edith Piaf or Aretha Franklin. The general vocal presentation is pretty upfront and intimate.

The Earsonics ONYX has a mildly warm and highly musical instrument tonality. Everything from guitars to violins, from trumpets to cellos are reproduced in a pretty lush and detailed manner. The ONYX is also a very successful Universal In-Ear Monitor in terms of separation and positioning of instruments and vocals.

For example, guitars do sound slightly warm, a bit bassy and very detailed, while violins do play in a moderately bright and mildly warm tonality, without to show any remarkable harshness and sibilance. Cellos on the other hand are soft, while the contrabass are lightly pronounced and fast.

The general midrange character of the Earsonics ONYX can be described as highly detailed, rich and pretty musical, with both male & female vocals and while listen to instruments from stings to brass instruments.



The Earsonics shows a silky smooth yet pretty detailed treble tuning with a fairly bold and moderately bright treble character, which can be classified as true HiFi like treble presentation.

However, the ONYX offers also enough airiness and sparkle in the treble area to prevent any type of congestions and muddiness while listen to a wide variety of music genres, which makes it to a perfect all-rounder in this area for a wide variety of genres.

The transitions from the upper midrange towards the lower treble region are in general highly controlled in moments when instruments or soprano vocals are reproduced with high level of distortion.

Instruments such as hi-hats, ride or crash cymbals do sound nicely pronounced, while the sense of intensity and extension is on a decent level, which surprisingly good for a Universal IEM with an overall warm (typical Earsonics) tonality.

The treble region extends quite smoothly, especially towards the upper treble region. This area shows a pretty efficient grade of clarity and definition and the fact that the lower treble range is nicely bright and well extending adds the overall presentation a nice sense of dynamism and energy.

All in all, the general treble presentation of the Earsonics ONYX can be described as silky smooth and fatigue-free, while it offers a very easy to listen to treble experience, which makes it also very ideal for longer listening periods.


Soundstage & Imaging:

The Earsonics ONYX shows a pretty holographic soundstage presentation that offers a good sense of separation between the right and the left channels, which makes it to a Universal In-Ear Monitor with a decent performance in terms of imaging. The soundstage shows an above average performance in terms of wideness and airiness, while it has a fairly natural sense of depth.





Some Comparisons:


Earsonics ONYX versus Oriveti OH500:

The Oriveti OH500 features also a Hybrid Driver configuration, which are 4BA + 1DD combinations that are located in an acrylic shell. The Oriveti OH500 has a lightly V shaped sound signature with a nicely done warm tonality and entertaining presentation. The bass is deep, warm and full bodied; the midrange is soft and musical, while the upper midrange and treble region is mildly bright and with good extension.

The subbass depth of both IEM’s is pretty similar, while the Oriveti OH500 shows slightly more intensity and rumble. However, the Earsonics ONYX is superior in terms of subbass authority, clarity and resolution. The midbass region of the OH500 is more highlighted and but a bit muddy compared to the ONYX, which offers a better sense of transparency, control and tightness.

The midrange of both In-Ear Monitors is successful in terms of detail retrieval and do share a warm tonality, while the OH500 shows a slightly warmer character in this area compared to the ONYX. Both IEM’s do offer a full bodied and emotional male vocal presentation, while the ONYX does have a better level of clarity and resolution. Female vocals do sound pretty lively and detailed with both IEM’s, however the ONYX shows a tad better level of clarity and resolution.

The upper midrange and treble region of both the Oriveti OH500 and the Earsonics ONYX is nicely highlighted, crisp and controlled, while the ONYX sounds slightly more natural and detailed. The treble region of the ONYX shows a slightly better sense of extension compared to the OH500.

The soundstage of both the Earsonics ONYX and the Oriveti OH500 is pretty similar in terms of depth and wideness, while the ONYX has a slightly advantage when it comes to the level of airiness and transparency.



Earsonics ONYX versus Dunu DK-4001:

Both In-Ear Monitors do come with a Hybrid Driver configuration. The main difference is that the ONYX is equipped with a 3BA+1DD configuration, while the DK-4001 utilizes a 4BA +1DD driver setup.

The Earsonics ONYX has the upper hand in terms of subbass depth, intensity and extension, while both are successful in terms of control and clarity in this area. When it comes to the midbass area, I can say that the Dunu DK-4001 shows less impact and authority in this area, while the difference in terms of resolution is fairly minimal.

The midrange of the Earsonics ONYX has a more forward oriented, intimate and somewhat denser and warmer tonality, compared to the Dunu DK-4001, which shows a slightly more dry and thin character that sounds a bit unnatural, especially when I do listen to female vocals.

Both the Earsonics ONYX and Dunu DK-4001 do offer a pretty controlled and fatigue-free treble presentation. The lower treble range of ONYX is superior in terms of clarity and definition. It offers also a more natural sense of airiness and sparkle in the upper treble register. The ONYX has in general the upper hand in terms of resolution, brightness and extension in the treble area.

Both In-Ear Monitors are pretty successful in terms of separation a placement of instruments and vocals. The main difference is that the Earsonics ONYX has the slightly edge in terms of soundstage wideness, while the DUNU DK-4001 has the upper hand when it comes to the depth of the stage.




The Earsonics ONYX is a solid Universal IEM, both in terms of construction and overall sound performance. The gorgeous looking Hand Assembled IEM with its Mat Metal Housing, which is 100% Made in France features a very well implemented and coherent sounding Hybrid Driver configuration that is able to produce a very rich, detailed and powerful sound presentation in High-End standards from the top to the bottom. All this features do come for a fairly affordable price, which makes the ONYX to a “Highly Recommended” product below the 500 EUR price range.




Pros and Cons:

  • + Powerful, Quick & Controlled Bass Response
  • + Rich Midrange Presentation with decent Level of Clarity and Resolution
  • + Liquid, Dynamic & Pretty/Silky Smooth Treble Tuning
  • + Solid Design
  • + Build like a Tank (Build Quality)
  • + Competitive Pricing


  • – Not the Richest Accessory Package (Simple Zipper Case, Small Number of Silicone Tips)
  • – Rock Solid Monitor Housing is a bit weighty
  • – A Balanced Cable or Modular Headphone Plug Design would be Welcome


Thank you for the Read!






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