I tested these clip-on open ear headphones with 3D audio – here’s how I rated them

Anker Soundcore C40i: review

Enter the Anker Soundcore C40i, another competitor in the ever-growing field of open ear headphones. Thanks to their lack of a seal, these clip-on headphones are ideal for those who want to be aware of their surroundings – such as runners or gym-goers. At the same time, the Anker Soundcore C40i still aim to deliver a strong sonic experience – something that a lot of open ear models have struggled to accomplish. So how do they fare?

Well, as you may expect, you’re not going to get stunning audio from the Anker Soundcore C40i. Like all open ear headphones, the loose design means that sound is less concentrated and there’s ambient noise to compete with from your surroundings. Yet these still perform decently in the audio department. Well, that is, after a bit of tinkering.

You see, out of the gate, I wasn’t sure if me and the Anker Soundcore C40i would be best pals. The default Soundcore Signature tuning is a little convoluted and bass packs a pretty feeble punch… well, more of a tap really. But I had no need to fear, because like many of the best open ear headphones, the C40i have custom EQ settings. I simply wandered over to the Soundcore app and refined audio by selecting 3D Surround Sound.

I was actually quite surprised that the 3D audio mode was a hit – I’ve seen no end of headphones fail on this, including rival clip-on buds like the Edifier LolliClip. Bass response is improved and you get a decently immersive listening experience – I stuck with 3D mode for much of my testing. There’s also a Bass, Volume Booster and an eight-band custom option for those who aren’t digging the 3D effects.

After getting all set up, I got straight into A Seagull & Clouds by Himiko Kikuchi, a beautiful funk-infused jazz track. The C40i performed very well for a pair of open ear headphones, with subtle percussive elements including tambourines coming through clearly, yet subtly enough to give the expressive trumpet, dancing keys and smooth bass plenty of limelight.

Moving over to Black Eye by Allie X and the pounding drum machine didn’t have the razor sharp speed that I’ve heard from more premium headphones, but its depth was replicated nicely, especially given the C40i’s open build. Higher pitched vocal segments sounded perfectly clear at medium volumes but could sound a little harsh at top levels.

Overall, I’d argue that the C40i sound above-average for a pair of open ear headphones. There’s no LDAC for ‘hi-res’ listening and you’re unlikely to be wowed by massive sub-bass, for example. But these do still offer up surprisingly good separation and impressively immersive overall sound, which is to be applauded.

There’s no noise cancelling here, as seen with some open ear headphones like the Honor Earbuds Open. And if you pair that with the C40i’s inherently leaky open design, you can expect listening sessions to be significantly interrupted if you’re in busy areas.

That could be a big win if you’re concerned about the risks of using ANC-enabled buds in traffic-heavy areas for your morning run. But if you’re instead looking to shut out the world around you, don’t worry – you can check out our guide to the best noise cancelling earbuds instead!

In general, there really aren’t a ton of features to play around with on the Soundcore C40i. Again, you can adjust EQ in the super easy-to-use app, which also shows devices connected with multi-point and battery life remaining for each bud and the charging case. The only other major inclusion is customizable button controls. You can assign a different function to tapping once, twice, or three times on the buds’ buttons. Options include playback control, voice assistant activation and volume adjustment.

The decision to use traditional button controls was also one that I had no issue with whatsoever. Sure, it’s not the most modern approach, but it removes the frustration I’ve experienced when accidentally triggering touch commands on rivals like the Happy Plugs Clip. These buttons also let you take or reject calls, which brings me onto mic quality. I found the C40i performed nicely, with clear speech on both calls and a voice recording. Background static was very limited and I wasn’t subjected to harsh sibilance either – no complaints here!

Outside of their button controls, I didn’t quite fall in love with the C40i’s design, though. Firstly, they’re not particularly pretty, with the Midnight model I tested having an almost muddy shade to it. The case also feels a little chunky and positioning the sync button on the underside of the case is a little odd – not that I really needed it thanks to the C40i automatically pairing to my phone via Bluetooth 5.4.

I also didn’t find these open ear headphones to be particularly comfortable. They were a little tight for me, so I rarely found myself keeping them on for longer than a couple of hours at a time. That’s something that the slightly newer, more expensive model, the Anker Soundcore AeroClip corrected with a more flexible build.

A couple more things before I stop moaning – both the C40i’s waterproofing and battery life are markedly average, with a number of competitors outperforming them. They’re just IPX4-rated, meaning they can handle some water splashes and sweat, but might not be the best with water jets or submersion. That’s not the case for a model like the IP57-rated Huawei FreeArc, which have plenty of protection against the elements. And you’re getting a moderate eight hours of playtime from the buds and maximum 21 hours with the case – again, nothing special.

The C40i still plate up impressive audio in 3D sound mode and I’m a big fan of the Soundcore companion app, so their list price of $99.99 / £99.99 / AU$149.99 is hardly outrageous. But you can do better. Specifically, the newer Anker Soundcore AeroClip are a more rounded, comfortable pick and only cost a touch more. And if you’re on a tighter budget, you can grab an excellent budget alternative like the Huawei FreeArc, which I’ve spotted on sale for less than £80 fairly regularly – but more on these below.

Anker Soundcore C40i review: specs

Anker Soundcore C40i review: price and availability

• $99.99 / £99.99 / AU$149.99
• Launched in October 2024

The clip-styled Anker Soundcore C40i released in October 2024 alongside a more traditional open ear model, the Anker Soundcore Aerofit 2. You can grab this model in three colorways: Desert Bronze; Midnight (black); or my personal favorite, Champagne Mist, which is a see-through variant, similar to the Sony WF-C710.

The C40i launched with a list price of $99.99 / £99.99 / AU$149.99, which is in the budget-to-midrange category. It’s worth noting that this model is significantly pricier than its predecessor, the Anker Soundcore C30i, which are typically $69.99 / £59.99 / AU$99.99. On the other hand, you’ll have to shell out $129.99 / £129.99 (about AU$210) for the more recent (and superior) Anker Soundcore AeroClip.

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Anker Soundcore C40i review: also consider

Anker Soundcore C40i review: How I tested

• Tested during a one-week period
• Used in the office and while out in public
• Predominantly tested using Tidal

I tested the Anker Soundcore C40i across the course of a week, predominantly when working at Future Labs, but also when out and about. I played around with their full set of features, tuned in for casual and critical listening and assessed their quality across all EQ presets.

When listening to music, I made use of Tidal on my Samsung Galaxy S24 FE. As always, I ran through the TechRadar testing playlist, which includes tracks from a variety of genres and is optimized for assessing sound quality across the frequencies. I also blasted a ton of tunes from my personal music library and compared audio capabilities against the Soundcore AeroClip on ear headphones.

• First reviewed: May 2025
• Read more about how we test