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We compare products from their published specs and features; the verdicts below are our independent editorial opinions.
Updated: 2026-09-21 · 7 min read · Independent comparison
• CMF BY NOTHING Buds 2a — biggest strength: 42dB hybrid ANC with 8 hours per charge (35.5 hours with the case), 12.4mm bio-fiber drivers, Bluetooth 5.4 and a deep app for EQ, ANC levels and dual-device pairing.
• CMF BY NOTHING Buds 2a — biggest trade-off: It's a sealed in-ear design, so you lose ambient awareness, and the case is unusually tall (23mm) for a pocket.
• Eonini Open-Ear Earbuds — biggest strength: The earhook, stay-aware design — nothing plugs your canal, sound leakage is cut by up to 50% versus standard bone conduction, and IPX5 plus 10 hours per charge (40 total) suits sweaty training.
• Eonini Open-Ear Earbuds — biggest trade-off: No active noise cancelling — only ENC for calls — and Bluetooth 5.3 with a two-hour full charge rather than the faster charging of the CMF.
• Buy the CMF Buds 2a if you mainly listen on trains, planes and in noisy rooms and want to block the world out.
• Buy the Eonini Open-Ear Earbuds if you run, cycle or lift and want your ears open to what's around you.
The Buds 2a is built around one idea: shut the world out and put bass in your head. The 12.4mm bio-fiber dynamic driver is co-tuned with DIRAC, and the spec sheet leans warm — rich mids, what CMF describes as thundering bass, plus a custom EQ in the Nothing X app if the stock tuning isn't your taste. The headline number is 42dB hybrid active noise cancelling, which is the kind of figure you buy for a bus, a shared office or a flight. There's a transparent mode too, so you're not locked out of the room when someone talks to you.
The practical details are where it earns its place. You get 8 hours of earbud playtime and 35.5 hours with the case, and a 5-minute quick charge returns roughly 2 hours of playback — useful when you remember to charge five minutes before leaving. Bluetooth 5.4 brings Google Fast Pair and Microsoft Quick Switch, and the app adds dual-device connectivity, a low-latency gaming mode of 120ms, find-my-earbuds and a ChatGPT shortcut when paired with a Nothing or CMF phone. Four mics with Clear Voice Tech and Wind Noise Reduction 2.0 handle calls, and IP54 plus a lanyard-ready case make it a reasonable gym or drizzle companion.
Who should buy it: commuters, students, hybrid workers, anyone who wants a sealed in-ear with real ANC and doesn't mind a plastic build in orange. Who should skip it: runners and cyclists who need to hear cars and other people. Sealed tips mean you trade awareness for quiet — that's the whole deal here. Also skip it if you hate in-ear pressure; the package includes S, M and L tips, but it's still a canal-sealing bud. The case is a 5.5cm square but 23mm thick, so it's chunkier in a jeans pocket than the flat pill cases some rivals use.
The Eonini Y70 goes the opposite direction. Instead of sealing your ear canal, it hangs a driver outside it on soft over-ear hooks. The result is the thing open-ear buyers actually want: you hear your podcast and the car behind you at the same time. Eonini claims sound leakage is reduced by up to 50% compared with standard bone conduction headphones, and the targeted projection design aims audio at your ear rather than the room. No vibrations, no canal pressure, no ear fatigue — that's the pitch, and it's a genuine benefit if in-ears have always made your ears ache after an hour.
Battery is 10 hours per charge plus 30 more in the display case, for 40 hours total, with a 5-minute quick charge giving about an hour of playback. The case has an LED readout so you can see the remaining charge without opening an app. IPX5 covers sweat, rain and splashes, which is the correct rating for running and gym work, and the ergonomic over-ear hooks are designed to hold during high-intensity training. Bluetooth 5.3 with touch controls, ENC for calls, Siri support and the ability to use either earbud independently round out the feature set. The build is ABS with silicone, in black.
Who should buy it: runners, cyclists, gym-goers, walkers in busy areas, delivery riders, and anyone who wants situational awareness or simply can't tolerate in-ear tips. Who should skip it: anyone chasing maximum isolation. If your main listening happens on a noisy train or open-plan office, an open-ear design lets that noise straight in — that's physics, not a flaw. Keep in mind there's no ANC here, only ENC for your voice on calls, and a full charge takes about two hours.
Side-by-Side: Which Should You Choose?
• Best for noise cancelling → CMF BY NOTHING Buds 2a. 42dB hybrid ANC with adjustable levels and a transparent mode; the Eonini has no ANC at all.
• Best for total battery life → Eonini Open-Ear Earbuds. 40 hours total (10 + 30) versus 35.5 hours (8 + 35.5 with case) on the CMF.
• Best for quick top-ups → CMF BY NOTHING Buds 2a. A 5-minute charge returns up to 2 hours of playtime, roughly double the Eonini's 1 hour from 5 minutes.
• Best for running, cycling and sweaty training → Eonini Open-Ear Earbuds. IPX5 plus secure over-ear hooks beats IP54 on sealed buds that can slip when wet.
• Best for call clarity in wind → CMF BY NOTHING Buds 2a. Four mics with Clear Voice Tech and Wind Noise Reduction 2.0 is the more specialised setup on paper.
• Best for app control and customisation → CMF BY NOTHING Buds 2a. Custom EQ, ANC levels, dual-device pairing, low-lag gaming mode and find-my-earbuds live in the Nothing X app.
• Best for all-day comfort without ear pressure → Eonini Open-Ear Earbuds. Nothing enters the ear canal, which is the whole point of the hook design.
If I had to pick one, I'd buy the CMF BY NOTHING Buds 2a — in my opinion it's the more complete everyday earbud, because noise cancelling, app-level customisation, four-mic call handling and Bluetooth 5.4 are the features most people touch every single day. The Eonini is the better tool for one specific job: training and commuting on foot or bike with your ears open. If that's your life, buy the Eonini and don't look back. If you want one pair that covers the office, the bus and the sofa, take the CMF.
They solve different problems, so "worth it" depends on your use. The CMF gives you ANC, richer bass tuning and deeper app control; the Eonini gives you open-ear awareness, IPX5 and longer total battery. For noisy environments the CMF is the more capable pair.
Do the Eonini Open-Ear Earbuds have noise cancelling?
No. The Eonini has Environmental Noise Cancellation for calls only — it cleans up your voice on the mic, but it doesn't block sound for the listener. If you want to silence a commute, the CMF Buds 2a's 42dB hybrid ANC is the feature you're actually after.
Yes — the Eonini is rated IPX5, which covers sweat, rain and splashes, and the over-ear hooks are designed to stay put during high-intensity training. The CMF Buds 2a is IP54, which handles dust and splashing water but is the lighter rating of the two.
Per the spec sheets: CMF Buds 2a gives 8 hours per charge and 35.5 hours with the case, with a 5-minute charge adding up to 2 hours. Eonini gives 10 hours per charge and 40 hours total, with 5 minutes adding about 1 hour. Both take roughly 89 minutes and 2 hours respectively for a full charge, so the CMF tops up faster overall.
Prices move constantly on both, so check the current price on Amazon using the button on this page rather than trusting any figure you've seen elsewhere.
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