Sennheiser is a big name, which is just as well when you consider how big its true wireless in-ear headphones are. Some brands value ‘discretion’ where products like this are concerned. Sennheiser, it’s safe to say, does not.
Happily, though, the ‘Plus’ in the model name here doesn’t mean these earbuds are even larger than the (already quite large) CX True Wireless on which they’re closely based. Rather they’ve had their specification ‘plussed’ with active noise-cancelling (ANC) and compatibility with Qualcomm’s aptX Adaptive Bluetooth codec – which is a fairly big thing at this sort of money.
So are the CX Plus True Wireless ready to be the next big thing in the world of wireless earbuds?
The Sennheiser CX Plus True Wireless are on sale now, and in the UK they’re selling for around £129. In America the asking price is more like $179, while in Australia you’ll need to part with AU$259 or so.
You don’t need to conduct an exhaustive search of this website to find similar money brings all sorts of very capable alternative designs into play. Just as a for-instance, there are models from Sony, from Panasonic, from Cambridge Audio and from Sennheiser itself costing this sort of money, that we’ve already reviewed and found very acceptable indeed.
In other words, the CX Plus True Wireless have their work cut out.
In terms of pure functionality, the CX Plus True Wireless are very competitively specified. That aptX Adaptive codec compatibility comes as a part of Sennheiser's Bluetooth 5.2 wireless connectivity, which is currently about as good as wireless connectivity gets. And once the audio information is on board, it’s delivered to your ears by a couple of Sennheiser’s ‘TrueResponse’ 7mm transducers.
Each earbud weighs just 6g (which is less than seems likely, given the size of the ‘buds themselves) and their charging case is a reasonably trim 59 x 34 x 43mm (hwd). The earbuds hold around eight hour’s-worth of power, with a couple of full charges stored in the case – an all-in total of 24 hours isn’t bad, but neither is it anywhere near class-leading. Should the worst happen, though, the CX Plus will go from ‘flat’ to ‘full’ in an hour and a half, while just 10 minutes on the mains will buy you an hour or so of playtime.
Getting your bidding done by the Sennheisers is straightforward enough. Google Assistant and Siri are both available (though you need to use the touch-controls to wake them), and both are alert and responsive. The touch-controls themselves take the form of a large capacitive surface on each earbud, and here’s where you can deal with all the fundamentals (‘play/pause’, ‘volume up/down’, ‘skip forwards/backwards’, ‘answer/end/reject call’, ‘wake voice assistant’ and cycle through your noise-cancellation options).
Alternatively, there’s always the Sennheiser Smart Control App – it’s far from the most extensive, but it lets you take care of all the obvious controls. Switch active noise-cancellation to your preferred position (‘on’/’off’/’transparent’), fiddle with a three-band EQ, adjust the amount of your own voice you hear during calls, turn on ‘bass boost’ (and then turn it off again straight away…).
True wireless in-ear headphones seldom get designed in any meaningful sense, and that goes double where Sennheiser is concerned. The CX Plus True Wireless are similarly functional, similarly utilitarian and similarly gawky to the CX True Wireless on which they’re based. Don’t imagine for a moment there will be any confusion as to whether or not you’re wearing them.
Still, the shape is decently ergonomic, the fit is comfortable (thanks in part to a wide selection of eartip sizes) and the relative bulk of the earbuds means there’s plenty of room both for the capacitive touch-surface we mentioned and for a couple of mics. Unarguable build quality and a choice of white or black finishes just about round things off.
These Sennheisers are a gratifyingly straightforward listen right from the off. There’s no slow-burn here, no revealing their true nature over time – just feed in a hi-res digital audio file from any of the streaming services that provide them, and the CX Plus True Wireless will tell you what’s what from the get-go.
With a 24bit/96kHz file of Jon Hopkins & Kelly Lee Owens’ Luminous Spaces playing, for instance, they’re a detailed and punchy listen – both in the moments when the recording requires it and sometimes even when it doesn’t.
The overall tonality is fairly even and pretty convincing. Treble sounds are just the right side of ‘overconfident’, but they’re packed with information and don’t lose control even if you wind the volume right up. The opposite end of the frequency range has depth, substance and is properly straight-edged where attack and decay of specific sounds is concerned. And in between there’s enough detail revealed to make even this gauzy vocal sound characterful and quite immediate.
This is a straightforward enough four-to-the-floor recording when it finally kicks off, though, and during those moments the CX Plus True Wireless reveal a less than instinctive way with rhythmic precision and expression. For all their punch and momentum, they’re not the most natural where disciplines such as this are concerned.
Frequency response 100Hz-10kHz
Microphone 2 x mic beamforming arrays
Speaker type TrueResponse Transducer 7mm dynamic driver
Waterproof rating IPX4
Battery life 24 hours
Codec support ACC, aptX, SBC, aptX adaptive
Dimensions (earbuds and case) 49 x 33.8 x 42.3mm
Weight 47g (earbuds and case); 6g each bud
Switch to a TIDAL Masters file of Lana Del Rey’s If You Lie Down With Me and those pros and cons remain unaltered, but this recording is also a little more revealing of the Sennheisers’ ability with dynamic subtlety and positivity. As far as the broad strokes are concerned, the CX Plus True Wireless have next-to-no problems – they can do ‘quiet’, they can do ‘loud’ and they can go from one state to the other in a heartbeat. But where the harmonic variance in an instrument, or the nuanced dynamics of a vocal performance are concerned, they’re really nothing special.
All of this assumes EQ settings that are left well alone, of course – as with any app that includes EQ adjustment, it’s possible to fundamentally alter the balance of the Sennheisers, but seldom in any kind of positive way. And it also assumes active noise-cancellation circuitry that’s switched on.
Unlike some competing designs, the CX Plus True Wireless don’t significantly alter their sound depending on whether or not noise-cancellation is enabled – which is good. But there’s not a huge amount of difference to the amount of external sound that’s discernible, either – switch it on and exterior noise is reduced a little, but not to the extent some (mostly a little more expensive) rivals can manage.
Obviously you’re spoiled for choice right now where true wireless in-ears are concerned, so Sennheiser is to be congratulated for managing to differentiate the CX Plus True Wireless from many of their price-comparable rivals. And when they’re good – with sonic punch and detail, for example, or their control options – they’re very good indeed. But a lack of rhythmic certainty, and their rather lumpy visual aesthetic, leaves the door ajar for plenty of alternatives.
- Sound 4
- Features 5
- Build 5
Read our Panasonic RZ-S500W review
And check out our Sennheiser CX 400BT review
These are the best true wireless earbuds: budget to premium