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KEF Mu3 Noise Cancelling True Wireless Earphones Review

Precise sound, active noise suppression for undisturbed music enjoyment, an outstanding design by Ross Lovegrove, an ergonomic shape for maximum comfort and a long battery life, the KEF Mu3 Noise Canceling True Wireless Earphones should offer all of this.

KEF Mu3 Noise Canceling True Wireless Earphones, at first glance these headphones can be used as a prime example of how a personal audio device can be designed in such a way that it can meet two essential criteria: on the one hand, the sound should be provided on the go, that one can expect from a well-known manufacturer like KEF, but it should also be a true lifestyle product, as headphones have to be these days.

In the following, we want to take a closer look at whether KEF succeeds in doing this as promised on closer inspection, and above all how KEF wants to achieve it, using a detailed test.

KEF – A very special company

There is no doubt that KEF is a very special company. The English loudspeaker specialist has always seen itself as a technology-driven company, and this characteristic is firmly rooted in KEF’s DNA and can be traced directly back to its founder, Raymond Cooke.

In 1961, Raymond Cooke founded KEF, and even in naming the company he was very pragmatic and simply named it after the place where it was based: Kent Engineering and Foundry.

As an engineer, Raymond Cooke was probably a rather pragmatic, solution-oriented person, but also a man who was driven by his love of music, and also by a certain unwillingness to compromise.

From the very beginning, KEF’s primary goal had been to fill rooms with music the way it was meant to be heard, to move people with truly authentic sound worlds. Excellence, that was what we had to strive for.

He pursued this goal throughout his life and the company in Maidstone is still committed to it and uses the most modern technologies in development and production to achieve it.

But then there is the other side of the coin, and that is the one that has been particularly evident over the last ten years or so. KEF has clearly set itself the goal of addressing a particularly broad target group, and accordingly places great value on realising extraordinary solutions, not only technologically, but also in terms of design.

Products such as KEF Muon, KEF Blade and KEF Blade 2, as well as the KEF LS50 and KEF LS50 META and their active sister KEF LS50 Wireless II are just a few outstanding examples.

Design plays an immensely important role, and this is where the cooperation with proven specialists is often relied upon.

Combining outstanding technology and exclusive design in the best possible way

If this is already the case in the classic loudspeaker segment, it is only natural to do the same in the area of personal audio devices, the segment to which KEF has dedicated itself intensively for quite some time and which has even become an essential pillar of the company.

Ever since KEF began developing headphones and portable Bluetooth speakers, the focus has been not only on the best possible technology, but also on the most exclusive design possible, whereby the company also relies on intensive collaboration with renowned specialists such as Porsche Design and Ross Lovegrove. The latter was also instrumental in the development of KEF’s latest product in the field of personal audio devices, the KEF Mu3 Noise Cancelling True Wireless Earphones.

Aesthetic design and impressive sound

KEF’s approach to the development of the KEF Mu3 Noise Cancelling True Wireless Earphones is to offer an aesthetically pleasing design with impressive sound, while relying on modern features and providing the highest level of wearing comfort.

Let’s start our review of the KEF Mu3 Noise Cancelling True Wireless Earphones with the most striking feature, the design.

Sculptural design by Ross Lovegrove

As described, renowned industrial designer Ross Lovegrove is also responsible for the KEF Mu3 Noise Cancelling True Wireless Earphones. He also designed the KEF Muon, the KEF Blade and KEF Blade 2, and even the KEF Muo portable Bluetooth speaker.

And of course, Ross Lovegrove remained true to his design line with the in-ear headphones, too. One speaks of a sculptural design here, even if the dimensions of 24.5 x 17.5 x 26.3 mm are ultimately very tiny solutions that, by the way, weigh in at no more than 5.8 g.

The curved, natural-looking design of the KEF Mu3 is advantageous in two respects: on the one hand, it results in an ergonomic shape, so that the headphones sit very well in the ear cup, and on the other hand, it is also optimal from an acoustic point of view, as there is no need to worry about resonances damaging the sound inside.

Ross Lovegrove also designed the transport case, which is of course included in the scope of delivery, in his typical design, but at 33.5 x 62 x 52 mm, it is a little larger than it should be.

On the other hand, it looks extremely elegant, conveys a very high-quality character from the very first impression and still fits easily into any pocket anyway, even in a trouser pocket, so that the headphones are always with you. The fact that it weighs only 46.8 g should also be mentioned, as well as the fact that these are certified according to IPX5 and are thus not only suitable for all weather conditions, but also for sports.

High wearing comfort

One very important point has already been mentioned, namely a high level of wearing comfort, which, as described, is already provided by the ergonomic design of the KEF Mu3 Noise Cancelling True Wireless Earphones. In addition, the manufacturer speaks of an intelligent weighting for an optimal balance, so that a secure hold without pressing is also guaranteed.

In fact, the in-ear headphones disappear almost completely into the ear cup, and the four silicone earmoulds included in the scope of delivery allow the user to choose the best possible size for him or her, in order to ensure not only an optimal fit but also the best sound.

Because only if the in-ear headphones are optimally fitted in the auditory canal with the help of the right earpieces, the right sound balance is guaranteed, this should be expressly emphasised once again. Apart from the fact that this already guarantees a very good passive shielding against ambient noise.

It’s a bit of a shame that the KEF Mu3 Noise Cancelling True Wireless Earphones only come with four earpieces, but KEF explains this by saying that a comprehensive analysis of different ear shapes and sizes led to the development of four slightly different sized earpieces. These are designed so that they hardly need to be inserted into the ear canal, which suits the taste of many users. Nevertheless, with the most comfortable fit, a perfect seal for noise insulation and a secure hold should be ensured at the same time. This, by the way, also explains why the pass pieces are called large, medium, small and short.

Full-range drivers for balanced sound

KEF relies on so-called full-range drivers for the KEF Mu3, which have a diameter of 8.2 mm and have been tuned by the same acoustic engineers who are responsible for the company’s speaker systems. This is to ensure that customers get exactly the sound characteristics they expect from a KEF branded product.

As is always the case with Bluetooth headphones, the information about the driver is ultimately determined by the signal transmission and is therefore not really very meaningful. For the sake of completeness, however, it should be mentioned that the impedance is specified as 16 ohms, the sensitivity is 104 dB, and the frequency range is said to extend from 20 Hz to 20 kHz.

  • Foto © KEF | KEF Mu3 Noise Cancelling True Wireless Earphones
  • Foto © KEF | KEF Mu3 Noise Cancelling True Wireless Earphones
  • Foto © KEF | KEF Mu3 Noise Cancelling True Wireless Earphones
  • Foto © KEF | KEF Mu3 Noise Cancelling True Wireless Earphones
  • Foto © KEF | KEF Mu3 Noise Cancelling True Wireless Earphones
  • Foto © KEF | KEF Mu3 Noise Cancelling True Wireless Earphones
  • Foto © KEF | KEF Mu3 Noise Cancelling True Wireless Earphones
  • Foto © KEF | KEF Mu3 Noise Cancelling True Wireless Earphones

Bluetooth 5.0 with SBC and AAC

Bluetooth 5.0 and the SBC and AAC codecs are used for signal transmission. This makes it clear that the KEF Mu3 are primarily designed for smartphones as a source, because higher resolution codecs such as aptX or even aptX HD or LDAC, which would be relevant for interaction with portable hi-res audio players, are not supported here.

Of course, the KEF Mu3s have built-in microphones so that they can be used as a hands-free device in conjunction with a smartphone.

Active noise cancellation

Even though the KEF Mu3 already offer extensive passive shielding from ambient noise thanks to their excellent fit, they also feature Active Noise Cancelling.

This is a specially tuned Active Noise Cancelling technology that is designed to effectively block out outside noise, but reproduce all the details of music playback without degradation.

This also means that the DSP-based signal processing itself should not cause any interference, such as background noise during pauses in music playback or during quiet music passages.

Another important feature is the Ambient Aware mode. In this mode, the surroundings can be perceived again at the touch of a button, so that the user is not completely disconnected from his or her surroundings.

Simple, intuitive operation

The KEF Mu3 is easy to use and intuitive to operate, with buttons on the outside of the earpieces being used in the tried and tested manner.

It should be noted that these are actually buttons and not just sensor keypads, which in our opinion results in more controlled operation, as not every touch of the ear tips leads to some kind of reaction. You do have to press gently, but still deliberately, on the KEF Mu3s….

Both the left and right earpieces have these so-called multi-function buttons, which are the central user interface from initial pairing to everyday playback control, volume control and answering/ending phone calls in conjunction with status LEDs.

You can simply try out what a left or right button press does in different situations, but it is probably more useful to take a look at the compact description in the package. After a few days, you will have internalised the operation anyway.

No separate app

Yes, you read that right, KEF does not offer an app for these True Wireless In-ear headphones. You don’t need it, according to the clear statement of the manufacturer, who deliberately made sure that the complete operation, as just described, can be done entirely with the buttons directly on the ear tips.

All those users who are annoyed by the flood of apps for all kinds of devices will find exactly the right solution here.

Nevertheless, the KEF Mu3s prove to be “smart”, because of course nothing stands in the way of using them for voice control via smartphone, be it Google Assistant on smartphones with Google Android, or Apple Siri on Apple iPhones with Apple iOS.

KEF Mu3 Noise Cancelling True Wireless Earphones im Test 19KEF Mu3 Noise Cancelling True Wireless Earphones im Test 20
Foto © KEF | KEF Mu3 Noise Cancelling True Wireless Earphones

Music enjoyment for the whole day

The KEF Mu3’s official playback time is nine hours, which would be very impressive, especially for true wireless in-ear headphones with such compact dimensions and active noise cancellation activated, if this figure is also met in practice.

And indeed, our test shows that you can get close to these nine hours, at least if you really enjoy music at a moderate volume and don’t abuse your eardrums at too loud a level anyway.

The KEF Mu3 are equipped with a 55 mAh lithium-ion battery, which is also included in the transport box, but with 500 mAh.

That’s enough for another 15 hours of playing time away from the power socket. Here, too, our test proves that the official manufacturer’s specification is quite realistic in practice.

Five minutes of charging for an hour of music enjoyment

What is particularly exciting in this context is that only five minutes in the transport box are enough to enjoy an hour of music again. This not only gets you through a day without any problems, but can also be used for a weekend trip without having to carry an additional power supply unit in your luggage.

The transport box and ultimately the headphones themselves are of course charged via a USB port, whereby fortunately a USB-C port has already been chosen. The corresponding cable – USB-A to USB-C – is of course included in the scope of delivery and has a practical length of just under 60 cm. In addition, it is also worth mentioning that it is of very high quality and therefore stable.

From the field

Because KEF focuses so much on the special design of the KEF Mu3 Noise Cancelling True Wireless Earphones, and thus sees them quite clearly as lifestyle solutions, the overall picture is of course relevant, and that starts with unpacking the headphones.

Here, manufacturers such as Apple Corporation have set standards and KEF does not show any weakness in this respect either. The packaging alone, the way the user can hold the product in his hands for the first time after purchase, all this already decides whether it is perceived as a high-quality solution and that is perfectly solved here.

KEF deliberately does without an app, so all you have to do is take the KEF Mu3 out of the box, pair it with your smartphone and you’re ready to enjoy your music.

Pairing works perfectly, and always reliably and quickly, as our test shows. Headphones, especially in-ear headphones, can be quite bitchy, but not so the KEF Mu3.

We can even state that the KEF Mu3 are by far the most uncomplicated solution when it comes to reliable, automatic connection with the source device. As soon as you open the transport box, they are already connected to your smartphone. This is done even before you take out the earplugs.

And even changing the source device is possible here at any time without any problems, simply hold down the multifunction button for a longer time and the voice “Ready to pair” sounds and you can connect them to another smartphone.

Once you have spent a few days with the KEF Mu3 in your ears and have memorised the most important operating functions, the complete operation proves to be just as simple.

As described, we like the design as a real button much better than a pure sensor keypad, because you can correct the position of the earplugs without accidentally jumping forward or backward in the playback, stopping the playback or changing the volume.

Of course, we would also like to praise the high wearing comfort, even if we would have liked to see one or two more earpieces in the scope of delivery. But even so, the KEF Mu3 headphones prove to be extremely comfortable to wear, even over long periods of use.

And the excellent battery life invites you to enjoy music with the KEF Mu3 for many, many hours, which is another plus point.

With the KEF Mu3, by the way, you can really talk about music enjoyment. These True Wireless in-ear headphones deliver a remarkably detailed and dynamic sound that inspires. They clearly reproduce all the nuances of the music, with the sound philosophy that KEF is known for in the field of loudspeaker systems. However, we wouldn’t call the sound characteristics absolutely neutral, because there is a slight accent in the bass and mid-range, which doesn’t do any harm with in-ear headphones, especially if you want to relax and enjoy music for hours without analysing all the details.

The integrated Active Noise Cancellation function ensures that this music enjoyment is undisturbed even in noisy surroundings and is characterised by its efficient mode of operation. The fact that this can be activated or deactivated quickly at the touch of a button is extremely practical in practice.

Despite all the enthusiasm for the KEF Mu3, there is one point that we must criticise: the fact that only SBC and AAC are used as codecs for Bluetooth signal transmission. Admittedly, the majority of customers will probably only use these headphones with a smartphone, which in many cases is an Apple iPhone and therefore does not support more than AAC anyway, but we are probably giving away a little potential here when it comes to smartphones with Google Android, which are often capable of more.

Finally, the KEF Mu3 Noise Cancelling True Wireless Earphones are offered in two versions, Silver Grey and Charcoal Grey. Judging by the features, the simple handling, the high wearing comfort, but above all the unique design and outstanding sound, we can give the KEF Mu3 Noise Cancelling True Wireless Earphones a clear recommendation.

Getting to the point

Our extensive review shows that KEF’s promise to offer a product that combines aesthetic design with impressive sound is fully fulfilled with the KEF Mu3 Noise Cancelling True Wireless Earphones. What’s more, the intuitive controls couldn’t be simpler, yet they offer all the flexibility you’d expect from such a solution. KEF clearly plays in the premium class of true wireless in-ear headphones and delivers a solution that deserves a clear recommendation.

Price€ 229,-
DistributionGP Acoustics GmbH
More about this manufacturer at HiFi BLOG

HiFiBLOG Award Excellent

Judging by the features, the simple handling, the high wearing comfort, but above all the unique design and outstanding sound, we can give the KEF Mu3 Noise Cancelling True Wireless Earphones a clear recommendation. Headphones that clearly play in the premium segment and skilfully combine lifestyle and excellent sound.


  • unique design
  • ergonomic design for high wearing comfort
  • very appealing sound
  • simple operation
  • effective noise cancelling
  • no app required


  • Unfortunately, only SBC and AAC are supported as Bluetooth codecs

Test Environment

  • Apple iPhone 12
  • Apple iPad Air
  • TIDAL HiFi



KEF promises music enjoyment for the whole day for the KEF Mu3 Noise Canceling True Wireless Earphones.

User Rating: 0.57 ( 3 votes)
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Michael Holzinger

Michael Holzinger, founder and editor-in-chief of HiFi BLOG and sempre-audio.at, has been working for years as a journalist in the fields of IT, photography, telecommunications and consumer electronics.

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