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We compare products from their published specs and features; the verdicts below are our independent editorial opinions.
If you want serious active noise cancellation, deep in-ear bass and marathon battery life, choose CMF BY NOTHING Buds 2; if you need to keep your ears open to traffic, your surroundings and your own conversations, choose Lsolrophon O3. These two earbuds sit in completely different worlds, and the wrong pick will frustrate you within a week.
• CMF BY NOTHING Buds 2 — biggest strength: Hybrid ANC rated at 48dB with a 5200Hz frequency range, plus up to 55 hours of total playtime and an IP55 rating. It's the isolation-and-endurance pick.
• CMF BY NOTHING Buds 2 — biggest trade-off: It's a sealed in-ear design, so you're cutting yourself off from the world on purpose, and the plastic build with rounded tips won't suit everyone's ear canal.
• Lsolrophon O3 — biggest strength: An open-ear hook design that leaves your ear canal completely free, with 13mm drivers, app-based EQ and IPX5 sweat resistance for training.
• Lsolrophon O3 — biggest trade-off: Open-ear means almost no passive isolation, and the battery figures are far more modest — 6 hours per charge, 30 hours total, with a 10-minute charge time listed rather than a full-charge time.
• Pick CMF BY NOTHING Buds 2 if you want to disappear into your music on a commute, a flight or a noisy office.
• Pick Lsolrophon O3 if you run outdoors, cycle, work in a shared space, or simply hate the feeling of something stuffed into your ear canal.
The Buds 2 is built around one idea: shut the world out. The headline number is 48dB of hybrid active noise cancellation covering a 5200Hz ultra-wide frequency range, and there's an Environmental Adaptive mode that adjusts the reduction level in real time as your surroundings change. In practice that means the drone of a train, a plane cabin or an open-plan office gets pushed down hard, and you don't have to fiddle with settings when you step from a quiet room into a loud street.
Sound is handled by an 11mm PMI dynamic driver tuned with Dirac Opteo, which the spec sheet describes as delivering deep bass and clear treble with precise instrument separation. There's also a 360° spatial audio effect powered by an HRTF-based algorithm, so films and games get a wider, more cinematic presentation. If you like bass, the Nothing X app lets you push the Ultra Bass setting and adjust EQ to taste.
Battery is where it really separates itself. Up to 13.5 hours on a single charge, 55 hours total with the case, and a 10-minute top-up that returns about 7.5 hours of playback. A full charge takes around 62 minutes, and the rated average life sits at 13 hours. Calls run through six microphones with AI-powered Clear Voice Technology 3.0 and Wind Noise Reduction 3.0.
Lsolrophon O3: Who It's For
The O3 goes the opposite direction. It's an open-ear design with adjustable ear hooks, soft silicone and a lightweight frame, so nothing enters your ear canal. The spec sheet's pitch is comfort without fatigue plus full awareness of your surroundings — you hear traffic, conversations and announcements while your music plays. For outdoor runners and cyclists, that's not a nice-to-have, it's the reason to buy.
Sound comes from 13mm dynamic drivers with a 20Hz–20,000Hz frequency range, and the companion app gives you personalized EQ modes plus custom button mapping. That app does more than EQ, though: it also handles real-time translation, with an input mode where you speak or type and hear the translation through the earbuds, and a conversation mode where two people speak in their own languages and the translated audio plays back. It connects over Bluetooth 5.4 and pairs under the name M117AI.
Battery is the clear weak point. Six hours of average life per charge and 30 hours total with the case, with a listed 10-minute charge time and an LED display on the case so you can see the level at a glance. Four AI-enhanced mics handle calls. IPX5 covers sweat and rain, which is enough for training but not for swimming or heavy downpours.
Who should buy it: runners, cyclists, gym-goers, people who work in shared offices and need to stay reachable, and anyone whose ears ache after an hour of in-ear buds. Who should skip it: anyone who wants to block out noise. There's no ANC here, and open-ear designs leak sound both ways.
• Best for noise cancellation → CMF BY NOTHING Buds 2. 48dB hybrid ANC with adaptive environmental mode versus none on the O3.
• Best for battery life → CMF BY NOTHING Buds 2. 13.5 hours per charge and 55 hours total, against 6 hours and 30 hours.
• Best for outdoor safety → Lsolrophon O3. The open-ear design keeps traffic and voices audible; the Buds 2 is designed to do the opposite.
• Best for workouts and sweat → Lsolrophon O3. IPX5 with adjustable ear hooks that lock the bud in place during movement. The Buds 2 has the higher IP55 rating, but it's a sealed in-ear fit that some people find unstable when they sweat.
• Best for bass and immersive listening → CMF BY NOTHING Buds 2. An 11mm driver with Dirac Opteo tuning, Ultra Bass in the app and 360° spatial audio.
• Best for long-wear comfort → Lsolrophon O3. No ear canal pressure at all, which matters if you wear earbuds for a full working day.
• Best for calls and smart features → CMF BY NOTHING Buds 2. Six mics with AI clear-voice processing and wind reduction, plus ChatGPT voice interaction via the app.
• Best for travel and translation → Lsolrophon O3. The app's real-time and conversation translation modes are genuinely unusual at this tier.
• Best for a long flight or a noisy commute → CMF BY NOTHING Buds 2. Nothing else here competes once the ambient noise floor rises.
If I had to buy one, I'd take the CMF BY NOTHING Buds 2. In my opinion, the combination of 48dB hybrid ANC, 55 hours of total playback and a 10-minute top-up that yields 7.5 hours is simply more useful in more situations — commuting, flying, working, gaming, watching films. The O3 is the better choice only if staying aware of your environment is the entire reason you're shopping, and for runners and cyclists that's a legitimate reason. Everyone else gets more from the Buds 2. Check the current price on Amazon before you commit, since both sit in the budget-to-mid range and the gap matters.
Not universally. The Buds 2 wins on noise cancellation, battery life and bass. The O3 wins on open-ear awareness, comfort for long wear and app-based translation. It depends entirely on whether you want to block sound out or stay connected to it.
No. The O3 is an open-ear design with no active noise cancellation listed. Because nothing seals your ear canal, ambient sound comes in naturally — that's the feature, not a flaw.
The CMF BY NOTHING Buds 2, by a wide margin. It's rated at up to 13.5 hours per charge and 55 hours total with the case, versus 6 hours per charge and 30 hours total for the O3. If you hate charging, that gap will decide it for you.
Yes. The adjustable ear hooks and IPX5 sweat and rain resistance are built for exactly that, and the open-ear fit means you'll hear traffic and gym announcements while you train.
I don't quote prices here, because they move around. Use the price button on this page to check the current figures on Amazon for both before deciding.
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See also: CMF BY NOTHING Buds 2a vs iDIGMALL Kids: Wireless Headphones, Razer Barracuda X Chroma vs CMF BY NOTHING Buds 2, CMF BY NOTHING Buds vs Avantree SoundJet R1&: Hybrid ANC