Review: Audio-Technica ATH-CKX9iS SonicFuel In-Ear Headphones

Even though Audio-Technica’s new ATH-CKX9iS SonicFuel ($100) is far from the most beautiful pair of earphones the company has ever released — we actually had trouble shooting good-looking photos of them — there’s no question that the design is otherwise appealing, and works exactly as expected. The idea behind ATH-CKX9iS is a fairly common one, namely to appeal to workout enthusiasts who need stable earbuds, and Audio-Technica handles this task with typical reliability.

Review: Audio-Technica ATH-CKX9iS SonicFuel In-Ear Headphones

Designed for active use, ATH-CKX9iS is a hybrid in-ear/earbud design, wrapping one piece of alien-looking silicone rubber around the earbud’s large 13.5mm driver, when using another piece of rubber as a tube to transport music into your ear canal. Audio-Technica includes three sizes of the alien-looking stabilizers to fit different outer ear sizes, plus four pairs of silicone ear tips and one set of Comply foam tips to isolate your ear canals. The earphones themselves are made from a mix of glossy black and silver plastics with matte black side accents, continuing to flat cabling that’s thin without feeling cheap, and a 3.5mm connector with an L-shaped housing. A zippered semi-hard carrying case is included in the package, and arguably more useful for holding all of the spare parts than the earphones themselves.


Review: Audio-Technica ATH-CKX9iS SonicFuel In-Ear Headphones

While ATH-CKX9iS looks a little odd thanks to tentacle-like partial loops on the stabilizers, the design impressively achieves its goal of stability while also offering legitimate comfort — the rubber doesn’t feel intrusive in your ears, and can be separately customized for outer and inner ear comfort with the included parts. The only functional compromise Audio-Technica really made here is in the remote control, which works around Apple’s standard three-button implementation by using a single multi-functional button a la early iPhones, plus a small side-mounted volume slider to manually attenuate audio levels. While you can’t completely turn the volume off with the slider, the controller otherwise works just like Apple’s three-button remotes, including Siri triggering, track-switching, and play/pause functionality. Microphone performance was slightly bassier than a standard Apple mic, but unobjectionable.


Review: Audio-Technica ATH-CKX9iS SonicFuel In-Ear Headphones

ATH-CKX9iS does well in the sonic department. While we wouldn’t describe the audio as mind-blowing in any way, it’s relatively bass-focused offset by clean treble, a balance that is fairly typical of sub-$100 earphones with respectable rather than remarkable detail levels. Music is played with the sort of “oomph” most budget-focused headphone buyers are expecting rather than a more clinical, neutral balance, and only critical listeners will note the absence of emphasis in the midrange. We’d expect performance like this from really good $50-$60 earphones sold without the stabilization, cable design, and pack-in frills.


Review: Audio-Technica ATH-CKX9iS SonicFuel In-Ear Headphones

Overall, ATH-CKX9iS is worthy of our strong general recommendation: it’s not gorgeous and the sound isn’t amazing, but it’s a very good option for active users who want far more stability and comfort from a pair of earbuds than they’d get from Apple’s EarPods or comparable $50 models. You’ll pay a bit of a premium for the enhancements and pack-ins here, but the investment will be worthwhile if you plan to run or work out with your iPod or iPhone.

Table of Contents

Our Rating


Company and Price

Company: Audio-Technica


Model: ATH-CKX9iS

Price: $100

Compatible: All iPads, iPhones, and iPods except iPod shuffle 3G

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