KEF Mu3 Wireless Earbuds Review

KEF Mu3 Review

Elegant design, sophisticated sound: the new Mu3 in-ear headphones from KEF want to make music lovers happy in every way. Whether on the way to work, in the home office, doing sports or relaxing in your free time. The British hi-fi experts at KEF have come up with a few ideas for this – both in terms of appearance and equipment. As a result, there is a lot of technical finesse in the small true wireless in-ears. And they sound perfect too!


  • Sound that is well-balanced and polished.
  • The finish is beautiful and the fit is comfortable.
  • Long-lasting battery


  • Short of sonic drive
  • No control app or EQ adjustment
  • Neither noise-cancelling nor call quality impress

KEF presents its newest Bluetooth headphones called KEF Mu3 quite self-confident and has some promises in the luggage: The “Noise Canceling True Wireless Headphones,” as the hi-fi company officially names its new product, are equipped with active noise suppression and a transparency mode. Combined with the current Bluetooth 5.0 standard and simultaneous control of both earbuds, the small headphones promise high connectivity and performance. The specified runtime of the Mu3 is a whopping nine hours. That’s enough for a flight from Frankfurt to New York. With the help of the charging case, the mileage can even be extended by a further 15 hours. And: The first five minutes of charging in the case should be enough for another hour of music enjoyment. These are just a few of the many features that the in-ears bring with them.

Charging case with style

First, the first thing is unpacked: In the high-quality packaging, the in-ears have made themselves comfortable in the said charging box. The scope of delivery also includes A USB-C charging cable, four pairs of silicone earplugs of different sizes, a quick start guide, and warranty information. Most of the time, a charging case only serves to transport the small earbuds and fill them with electricity safely. However, the silver box with the KEF logo on the lid meets far higher demands: it is a pleasure to look at and feel. If you open the flap, you immediately see the reason for this: The wireless headphones were designed in collaboration with the British industrial designer Ross Lovegrove. He is best known for his work on Sony’s 80s cult object “Walkman” and made a name for himself as an Apple partner. His innovative approach is legendary, and it is evident in all of his designs: the organically swinging design language that is his trademark.

Flowing Lovegrove design

The Briton has designed several products for his fellow countrymen at KEF since 2005. And now the “Lovegrove” lettering adorns the inside of the KEF box. The designer previously gave the wireless speaker Muo its charm. Even with the extravagant loudspeaker Muon, his signature is recognizable in the flowing, sculptural form. Now the visionary has “taken care” of the small buds. The silver in-ear headphones KEF Mu3 are ultimately a specific Lovegrove product. Artful, organic, flowing, harmonious, elegant – simply beautiful. The pure and clear aesthetics should perfectly complement KEF’s design philosophy. But just being beautiful is not enough. KEF has higher demands: The design of the KEF Mu3 also ensures a physically good balance of the headphones. This, paired with a selection of suitable earplugs, should enable a perfect fit. And the inner values ​​are also highly demanding: They were developed by the KEF-Akustik team to deliver an unadulterated, pure, precise, and high-resolution sound.

Completely thought-out earplugs

After charging the small box with the help of the supplied USB-C charging cable, I test the earplugs for their optimal fit. I almost always pull off the attachments that are too large (for my ears) and put the mini version on them. It only takes a few seconds to change – very good. And really: In combination with the ergonomic design, these attachments ensure ultimate comfort and a perfect fit. Furthermore, KEF promises that the KEF Mu3 in-ear headphones are prevented from falling out thanks to their intelligent weighting and the associated good fit in the ear. This will, of course, be tested intensively later. Incidentally, a comprehensive analysis of different ear shapes and sizes has led to the development of the four slightly different-sized plugs. These lie on the auricle to ensure the most comfortable fit while providing a perfect seal for noise isolation. On this point, too, the in-ears can prove themselves later.

Stable connection

KEF also relies on the latest findings when connecting to a mobile device: The audio performance of the KEF Mu3 is achieved through simultaneous transmission, in which both headphones receive an audio signal. Instead of passing signals from one headphone to the other, they are being received by both headphones simultaneously, avoiding any delay. In combination with the Bluetooth 5.0 connectivity, the Mu3 should deliver outstanding performance, be easy to connect, and work extremely stable with both iOS and Android devices. Pairing is straightforward. Once they are paired, the in-ears automatically connect immediately. You don’t even have to turn the futuristic buttons on or off. It is entirely sufficient to take them out of the charging box.

KEF Mu3 with precise sound

Charged, connected, so let’s start the practical test: I begin with Alicia Keys and “Underdog.” Delicate guitar sounds, plus Alicia’s unique voice. Every note penetrates my ears with a great deal of detail. Together this results in a perfectly arranged sound experience. The onset of bass blends in comfortably and maintains a nice balance with the other elements shown. After a few minutes, you can already say: The sound is extraordinarily dynamic and balanced for such small plugs. The reason for this: Each of the sculptural Mu3 headphones has a dynamic 8.2-millimeter full-range driver. It is tuned by the same engineers who are responsible for the KEF loudspeakers. So I experience a pure and precise sound with detailed mids, rich bass, and crisp highs even on the go. It continues with “For A Second” by Michael Schulte: Here, too, the KEF Mu3 scores from second with its joy in playing and dynamism. Everything is balanced and an absolute pleasure to listen to.

Noise suppression at its finest

So far, I’ve been listening to music in the usual standard model. Now it gets a little more challenging for the KEF headphones. For this, I choose a very everyday situation: The three other family members sit at the table and talk. With the music turned on, I can hear snippets of conversation in the distance, but I can’t begin to understand what it’s about in detail. Now I select active noise cancellation (Active Noise Cancellation Technology) by clicking on the left rear panel, confirmed by the announcement “ANC.” This is supposed to eliminate outside noise without affecting musical details. That works well! I see that the mouths are moving, but now I don’t understand anything. The music quality, however, remains almost constant. And that’s the real challenge with the ANC: Not filtering out sound nuances while attenuating ambient noise. KEF has taken this hurdle more than properly. But the earbuds can do even more: click again, and you will hear “Ambient.”

Perceive the environment

The headphones also have an “ambient mode.” If you activate this, the active noise suppression is partially deactivated. Instead, ambient noises recorded by the microphones are played back through the headphones. This bypasses passive noise suppression. I can now perceive everything that is happening around me. This is particularly advantageous if you are waiting for a train at the train station, cycling, or want to hear bicycle bells warning you while jogging. The music now moves slightly into the background, but the sound quality remains at a high level. This transparency mode also works excellently in my everyday situation: While in normal mode, I only understood distant scraps, and nothing got into my ears with the ANC. Can I follow the conversation now – that is fascinating. And another plus point for the KEF Mu3.

Endurance test for the Mu3

Before I pose any further challenges to the KEF Mu3, I’ll take a vacuum cleaner tour. Here, too, I will activate ANC again. My impression of the moment is confirmed immediately: The vacuum cleaner’s noise is clearly in the background. And about wearing comfort, I can already draw a first positive interim conclusion: Simply comfortable. The in-ears are pleasantly soft. There is no pressure at all. I am even wearing it for several hours, such as during a train ride, in the home office, at a video meeting with friends – no problem at all. Then I lace up my sports shoes and look for a podcast to go for a leisurely jog. My choice falls on “Toast Hawaii” with Bettina Rust, who Anke Engelke hosts. While this tells that she takes apples and bananas to the cinema and has an eggshell-colored kitchen, the KEFs don’t move slightly. They are also bombproof when you jump afterward.

Intuitive and prompt operation

While I’m now gasping for air, I’m looking for some relaxing music for the final stretching exercises. I’m going to test the operation via the touch panel on the earbuds. Each headphone has a multi-function button for complete control of music playback, volume, and calls. A short press on the right for play/pause. Double-tap to skip forward a track, press and hold to increase the volume. ANC and Ambient can be activated on the left. The operation works without any problems and is completely intuitive. What stands out compared to other models that I have already had here for test purposes: Often, you have to press the user interface so hard that it reacts that you feel the plug pushed deeper into your ear every time. Fortunately, this is not the case at all with the KEF model. The touch panel reacts promptly with a light “click.” A “push in the ear” is completely avoided—pure comfort.

One charge lasts for 24 hours.

Telephone calls can also be accepted, ended, or rejected at the touch of a button. The built-in microphones ensure excellent communication with the caller. Going for a walk on the phone or jogging with music in your ears is even possible in the rain. Thanks to the splash-proof design, the headphones stay safe even in moisture. Regardless of the weather, whether listening to music, listening to a podcast, or making a phone call – the Mu3 can last a full working day. After just under nine hours, they have to go to the charging case to recharge their batteries. On the way, the running time of the KEF-In-Ears can be extended by up to 15 hours via this detour. In total, a full charge lasts 24 hours. The quick charge function is also interesting: Five minutes in the stylish box provide around an hour of new power. After many hours in my ears, one thing is certain: The seat is super comfortable, and the earplugs are still pleasantly soft.


KEFs Mu3 combines aesthetic design with high-quality sound. Appearance and sound are equally convincing at the highest level. In terms of sound, we haven’t heard any better in-ears in this price range. In addition to the excellent sound quality and the flowing “Lovegrove” look, the Mu3s have a lot more to offer: Bluetooth 5.0, 24-hour operating time, comfortable fit, intuitive operation, quick-reacting touch surface. In addition, there is active noise cancellation and the ambient mode. Whether at work or in your free time: KEF leaves nothing to be desired in terms of wireless and powerful in-ear headphones with the Mu3.

KEF Mu3 Wireless Earbuds Review
KEF Mu3 Wireless Earbuds Review


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