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The CX True Wireless improve on their predecessor’s sound and features – but the competition has caught up and, in some respects, surpassed what Sennheiser is offering here.


  • Affordable price
  • Good seal and comfort
  • Improved battery life over CX 400BT


  • No ANC
  • Competition has caught up
  • Choppy connectivity in busy signal areas

Key Features

  • SoundFeatures Sennheiser’s TrueResponse transducer for less noise during playback
  • BatteryTwenty-seven-hour battery bests that of the CX 400BT
  • Bluetooth codecsSupports SBC, AAC, aptX


The Sennheiser CX 400BT were a Trusted Reviews favourite, winning the best affordable true wireless earbuds 2021 award. At first glance, the CX True Wireless appear identical.

And so, we presume the CX True Wireless (or CX 200BT) pick up right where the previous model left off. Is this the same award-winning sound as before, or have Sennheiser’s rivals stepped up their game?


  • UKRRP: £119.99
  • EuropeRRP: €129


  • Same looks as the CX 400BT
  • Good fit and effective seal
  • Not the most distinctive appearance

Put the CX True Wireless and CX 400BT side-by-side and the differences are few and far between. Practically the same weight, size and dimensions, if you were looking for a sense of evolution in Sennheiser’s design, you won’t find it here. My feeling is, “if it ain’t broke, don’t fix it”.

Sennheiser CX True Wireless view from side

So that means the touch panels remain square in shape and easy to locate, the only noticeable aesthetic difference being the Sennheiser logo is decorated in a muted black finish. Like most of Sennheiser’s earphones, the CX True Wireless come in either a black or white finish.

Comfort is good, touch controls are simple and responsive, while the passive noise isolating design proves effective. While active noise cancellation is appearing on more earbuds at this price – in fact, Sennheiser’s own CX Plus feature it – the CX nevertheless rebuff traffic and city noise from intruding on your playlists.

Sennheiser CX True Wireless underside

They don’t shut out noise completely, though, so you’re still able to get a sense of your surroundings, and with four ear-tip sizes included (XS, S, L alongside the default M), there’s room to find the best fit.

Another slight change is that the LED indicator on the charging case has been brought from the rear to the front, which makes more sense. Otherwise, it’s much the same as before.


  • Better battery life than the CX 400BT
  • Sidetone call feature more miss than hit
  • Wireless connection takes a hit in busy areas

Even though the case is the same size and shape, Sennheiser has prised out more battery life with the 9 and 27 hours in total besting the CX 400BT’s 6.5 and 20. Compared to other affordable true wireless, it’s respectable enough.

There’s no wireless charging, but there is fast charging. As such, 15 minutes is good for another 60 – although, oddly, that’s slower than the CX 400BT, where 10 minutes would give you 90 minutes.

The CX True Wireless will happily sign off with the native digital assistant on your mobile device (Alexa, Google Assistant and Siri), and like pretty much every set of earphones Sennheiser has released in recent years, it will couple with the Smart Control app (Android, iOS).

Sennheiser CX Smart Control app

While the app isn’t filled with features, there are the usual EQ settings, firmware updates and touch control customisation. But the CX True Wireless boast a few additional features over the CX 400BT in the ability to set a timer for Auto power-off, Bass Boost (more on that later) and Sidetone.

Sidetone allows you to hear your own voice during calls for – as Sennheiser calls it – a more comfortable experience. There’s a slider in the app, from 0 to 100, which increases how much of your voice you can hear.

However, it isn’t the most helpful. The tone of my voice sounded robotic during calls and adjusting the slider seemed to change how much noise the person on the other end of the line could hear. At 100% Sidetone my voice was louder but more robotic sounding, but at 50% there was more noise picked up.

Sennheiser CX True Wireless earbuds

In terms of call quality, the CX True Wireless put in above average performance. Even with the dual-mic set up on each earbud, the pickup of my voice was rather faint, with wind noise also audible according to the person on the other end of the line.

Back to the app, there are a few presets you can choose from in Neutral, Podcast, Movie and Bass Boost. Neutral is default, while there’s the option of creating your own customised preset. You can have Movie and Bass Boost at the same time, but you can’t use Bass Boost with Podcast. Podcast has its uses, widening the soundstage to provide more space to what’s being said.

Bluetooth connectivity is buffed up to version 5.2 version, but when I’ve worn the CX in busy areas and train stations, the connection has become very choppy. Codec support is the same with SBC, AAC and aptX, and the earbuds’ water-resistance remains identical to the CX 400BT at IPX4.

Sound quality

  • Improved sound over CX 400BT
  • Short of sharpness, detail and clarity versus rivals
  • Bass Boost via app

Most of this review of the CX True Wireless has come from the perspective that they’re more of the same. You’d assume then that this would apply to the sound as well. However, to my ears, Sennheiser has slightly tweaked its approach for the better.

That change is noticeable in the overall balance. While both the CX 400BT and CX True Wireless sound similar, the latter appear to have been tuned to extract more performance from higher frequencies, while the CX 400BT hit bass notes with more depth and weight.

Sennheiser CX True Wireless case open

Both models use 7mm drivers, the only difference being the newer CX model has Sennheiser’s TrueResponse technology. Sennheiser says that a benefit of using this single high-performance driver is that it produces less noise, and that played out during testing, with less audible hiss than the CX 400BT.

While the CX 400BT initially had the edge in terms of bass, the CX clawed it back with its Bass Boost. Turn it on and the bass response becomes more textured and weightier, and it achieves this without compromising the gains found in the upper frequency range. In fact, the CX True Wireless boast a greater, more spacious presence than the CX 400BT, which sounds more muted at lower volumes.

Sennheiser CX True Wireless outside

Compare the CX to the Beats Studio Buds, and it’s a bit of a seesaw in terms of which set of earbuds gets the upper hand. The Sennheisers spread the sound out wider, but also sound warmer, with detail not showcased to the same level as the Beats. There’s a fuzzy quality to the CX’s playback as the Studio Buds furnish tracks with more clarity and separation; instruments and backing vocals on Nuyorican Soul’s Runaway portrayed clearer on the Beats.

Move on to The Hands Dealt from the Doctor Strange soundtrack and the Beats’ high-frequency performance is sharper and again clearer, its grasp of more lively and energetic tracks is also more pronounced; the overall clarity, sharpness and dynamism afforded to Ludwig Göransson’s Ship o hoj, Mandalorian trumps the Sennheiser’s bigger, but thicker and imprecise sound by comparison.

The CX True Wireless presents a likable sound, but the margins between it and its rivals have closed.

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Should you buy it?

If you’re after affordable, non-ANC earbuds Not everyone wants noise cancellation, and if that’s you then these Sennheisers offer a solid listening experience with a few app features to customise the sound.

The competition has caught up and, in some respects, surpassed While the CX True Wireless sound better than the previous incarnation, the strength of competition means these aren’t the superior choice anymore. Factor in the lack of ANC for this model, and there isn’t as much value with these Sennheisers as you can get elsewhere.

Final thoughts

The Sennheiser CX True Wireless present something of a conundrum here. They sound better than the CX 400BT, but the gap between Sennheiser and the rest of competition has closed up to the point where the CX aren’t the superior choice.

While I can forgive the lack of app features to an extent, the general move towards active noise cancellation at this price means the CX don’t offer as much bang for the buck.

At a lower price the CX True Wireless’s virtues become clearer – but if you’re after ANC at an affordable price then even Sennheiser’s own CX Plus make the CX True Wireless rather redundant.

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We test every headphones we review thoroughly over an extended period of time. We use industry standard tests to compare features properly. We’ll always tell you what we find. We never, ever, accept money to review a product.

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Tested with real world use

Test over several weeks

Tested with music streaming services


Do the Sennheiser CX True Wireless have active noise cancellation?

No, but Sennheiser’s CX Plus earbuds do.

Full specs

IP rating
Battery Hours
Fast Charging
Release Date
Model Number
Driver (s)
Frequency Range
Headphone Type

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