At the gym: C-Ear X custom-moulded IEM review


The music we listen to behind headphones is private before it is personal. And private audio roughly subdivides into two areas:

1) In the home, at the office or staying in a hotel there is desk space upon which you can spread out your tablet/laptop, DAC, headphone amplifier and headphones. Your headphones can be as big as you please. They can be open back and leak sound to your surrounds. Wall-sockets are on hand for direct power or re-charging any or all devices.

2) Commuting on public transport, shopping around town, sunning at the beach or working out at the gym. In these scenarios more consideration must be given to the size and weight of your portable rig – it needs to fit in your pocket or slip easily into a bag and not disturb those around you. No-one enjoys sitting next to someone belting out tunes through open-back cans on the bus/train/ferry. You don’t wanna be that guy, do you? Not when you can turn this problem into advantage: noise cancellation and/or noise isolation. By keeping your music IN you keep external noise disturbances OUT. Win-win for you and your fellow humans. Headphones need to be earbuds/IEMs or closed back fold-aways.

November 2012. Post RMAF, too many Fat Tires had given me too many spare tyres – so I joined the gym. This story begins there. At Vision PT in Sydney’s inner-west suburb of Stanmore, the sounds of Beyonce, David Guetta, Lady Gaga dominate the room – emphatically not my cup of joe. Adding injury to insult, they play that shit TOO DAMN LOUD. As my Dad would say, “you can’t even hear yourself think”. There was zero hope of drowning it out with an iPhone + Apple earbuds, not without significant distortion and a risk of hearing damage. The gym had become a fresh audiophile battleground – a location that demanded the utmost in headphone portability and noise isolation.


A solution that could hold back the aural assault of Pitbull (ugh) and David Guetta (ugh x 1000) was needed. Noise cancelling efforts like the PSB M4U 2 are plainly too bulky for treadmill/bike. Ditto KEF M500, which are too loose a fit. The Martin Logan Mikros 90 (now discontinued) clamp tight to the head but sweat-up too easily. The Precor exercise bike is no place for full (or even medium) sized headphones. Even on-ear designs are a no go.

Earbuds didn’t cut it. Too loose a seal with the ear let too much Katy Perry in. IEMs are the only way to go. IEMs that can hold back the hell of Rihanna. I tried the RHA MA450i noise isolating (not cancelling) in-ears but found them to be nothing more than so-so; perfectly OK for the price – AU$60 – but far from satisfactory. The RHA in-ear come with a selection of detachable to tips to get the ear-seal just right. Once I’d found my size, isolation was reasonably good but the sound quality just wasn’t up to muster. That aside, too much cable noise was the RHA IEM’s most obvious flaw.

Enter Terence White, Australian distributor of Resonessence Labs products. Whilst tee-ing up review units of RL gear, White let it slip that he was also the Australian agent for C-Ear. C-Ear are a sub-brand of Germany’s KIND. They make IEMs. Not just any old IEMs, theirs are custom moulded.

No you can’t audition them before purchase – they’re a custom fit. I took a leap of faith, with the cliche of high-quality German engineering assisting nicely.

Getting personal. A few weeks after my initial phone enquiry/consultation I was having ear impassions taken at a nearby audiologist: foam is injected into each ear and allowed to set for ten minutes (see headline photo). These moulds are posted back to Mr. White who then forwards them onto KIND’s manufacturing facility in Germany. The impressions are 3D-scanned into a computer from which the ear-phone shells are injection-moulded with plastic (black or white – your choice) and then laser-engraved with your name and a serial number. The internal drivers are fitted and wired by hand. Turn around on this process is around 3-4 weeks.


The C-Ear V (AU$350) is the entry-level model: one driver handles all frequencies. Specs: 25 ohms, 105 db, 20Hz – 17kHz. I’d opted for the C-Ear X (AU$540) with twin drivers: one for midrange and treble, the other for bass frequencies, hence the better frequency range spec of 20Hz – 21kHz. Impedance on the C-Ear X is 130 ohms, efficiency 115 db.

The C-Ear X arrive with warranty card clipped to the front of the box – you get 12 months. Inside the box, a nice enough clamshell carry case. Nothing too flash but I didn’t use it once – it’s too bulky in the context of that which it is designed to protect. (I store my C-Ear IEMs in an unused Yuin ear phone container).

Inside the carry case: an in-flight adapter, cleaning cloth, eight replacement ‘CeruSTOP’ cerumen protection filters and (of course) the C-Ear X themselves. They don’t look much like normal in-ear ‘phones, do they? That’s because your ear canals are neither symmetrical nor cylindrical.


Do you remember the first time? I’ll confess to my right ear initially finding the fit somewhat uncomfortable. I suspect I’d tried to push the shell too far into the ear canal instead of letting it find its natural resting position. The irritation that ensued subsided after a week or so, Since then I’ve never looked back, both ears have enjoyed nothing but a perfect fit. And I mean perfect – 100% spot on. Moreover, the C-Ear X don’t become uncomfortable during extended use and they hold fast and true to position during the most vigorous of gym workouts. Worry not about sweat or your ear’s detritus. KIND ship their IEMs with replacement filters – see the two white circles at the business end of each shell? That’s them. Fitting a new filter is simple: remove with one end of the stork, attach a new one with the other.


World leader pretend. In a car, the window closes with a reassuring thrump. Just as the window makes a seal with the door frame you hear the last of the outside world being seemingly sucked from the scene. You get a similar sensation when fitting the second shell. It isn’t the quite the seal of tuppaware but you are double glazed to dumbness. The muffled drone of passing cars and the faint hum of nearby/close conversation is still discernible. The C-Ear X allow just enough ambient noise into the ear so as not to get you killed when crossing the road and you can just about hold a conversation without removing them. Just.

You’ll notice street noise to be far less irritating when on hight street walkabout. The sound of the city is dialled back to one (on the dial). At the gym, I found myself able to enjoy music (finally) without the likes of Flo-Rida or Calvin Harris being thrust into the mix.  Better still, this was possible without having to let the volume rip. Noise isolation is so effective with the C-Ear IEMs that you don’t need to crank them.  It’s your world and no-one else’s.


Listening impressions. Even with an iPhone 4 as source, the presentation communicates neutrality as one might intuit the implication of being teutonic – an ideal match for the techno (Planetary Assault Systems and Orbital) that propels me through my exercise routine. They’re not the airiest of listens, reminding me of Spendor’s SA1 in loudspeaker land, but they are exceedingly intimate. I’d venture that the C-Ear engineers were mandated to voice their IEMs as ‘closest to source at all costs’ (unlike the aforementioned Martin Logan Mikros 90). Bass depth and articulation is terrific. As is the C-Ear’s ability to trawl for detail, underlining most pleasure is likely to be derived from this IEM’s way with noise-isolation.

Being a super-fussy bastard, I have two very minor complaints. Reminiscent of the Austrian AKG K-701/2, the C-Ear X do connote occasional hints of dryness, predominantly with poorer recordings (The House of Love’s “Destroy The Heart”). Unlike the over-ear, open-backed AKGs, the C-Ear X also get a bit congested when the midrange gets busy (Pet Shop Boys “Axis”, Talking Heads “Memories Can’t Wait”, Arcade Fire “Reflektor”). Even then, midrange transparency is substantially better than any non-custom IEM that I’ve tried over the years.


Comparisons = zero. As such, a recommendation from a directly-experienced field of one would be meaningless. My message isn’t (necessarily) that you should rush out and buy a pair of C-Ear X, although I wouldn’t fault you if you did. They come with a four week, money-back ‘complete satisfaction’ guarantee. Instead, the big idea here is that investment in a custom-moulded IEM is terrific way of ensuring your listening experience goes largely undisturbed. The hyperbolic monster within me wants to proclaim the C-Ear X as revelatory. That these IEMs have transformed my gym listening experiences out of sight suggests such an emphatic conclusion isn’t beyond substantiation.

Know that the C-Ear X haven’t displaced my preference for full-size headphones at home; there the AKG K-702 reign supreme. However, when paired with the Astell&Kern AK120 portable media player, I’d liken what spills from the C-Ear X as as close to a home-listening experience as you’re likely to get whilst out and about. Note: the X model don’t play so nicely with the AK100’s higher output impedance – the sound is horribly rolled off; successful marriage is more likely between the AK100 and the (cheaper), single drive C-Ear V.

Wrap it up and start again. One thing I know for certain about audiophiles is that once they get infected with the ‘good-better-best sound’ virus, they don’t shake it. They optimise their main rig before attending to other rooms in the house, then the office and business trips, then weekenders and…and…and beyond. Beyond for me includes the gym and – in an article to come – the beach. In these contexts, where lightweight comfort and sound isolation sit at the very top on the priority list, the C-Ear X will make the most demanding of audiophiles happy, wherever s/he ventures. If nothing else, they’ll taking your gym listening experience from hell to hallelujah!


Associated Equipment

  • Astell&Kern AK120
  • iPhone 4


Audition Music

  • Planetary Assault Systems – Function 4 Remixes (2012)
  • Orbital – The Brown Album (1993)
  • Pet Shop Boys – Electric (2013)
  • The House of Love – The House of Love (1988)
  • Talking Heads – Fear of Music [HDTracks 24-96, 2005 remaster] (1979)
  • Arcade Fire – Reflektor [single] (2013)


Further information

Written by John H. Darko

John lives in the NOW + HERE = NOWHERE. He derives an income from the ad revenues of DAR. John is also an occasional staff writer for Stereophile, 6moons and TONEAudio.

Twitter: DarkoAudio
Instagram: DarkoAudio
Facebook: DAR


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  1. It takes an Aussie to advise a German that the good things are just around the corner 🙂 …. there’s a Kind shop only 800 m from my flat and I’ll catch an appointment this week. Thanks, John !

  2. In all fairness to the likes of Raekwon and Killer Mike not all rap is of the like that plagues most gyms.

    I occasionally find myself in one of the many pubs of the inner west and they often have the same rubbish playing through the jukebox. There’ll be 12 people in the place, all of them blokes, all of them having a drink and watching some variety of sport on the tv and yet music designed for 12 years olds is blaring…anyway, s’cuse the segue.

  3. You should try running Darko. You’re not stuck in the gym environment & it’s much better for your mental too. (plus the runners are hotter. Great for motivation)

    Once you’re hooked, you’ll never look back.

    Ps. Great new layout

  4. Hey Darko

    With regards to impedance of 130.ohms – how does that affect you if you using just a mobile phone as a source? Loudness?