KEF LS50 Wireless II Review

The first generation of the KEF LS50 Wireless active loudspeaker system already caused a sensation, and the second generation, in the form of the KEF LS50 Wireless II, aims once again to be a reference in its class, essentially a high-end hi-fi system in its most compact form.

It’s clear to say that the world of consumer electronics, especially in the field of high-end hi-fi, has undergone a massive transformation in recent years. It can also be said that solutions such as the KEF LS50 Wireless II from the English loudspeaker specialist KEF play a central role in this development, and some even say that such products represent the future of modern hi-fi.

This may seem exaggerated to some, but a close look at consumer behaviour clearly supports this claim.

Focusing on the essentials

Hi-fi in the classical sense has always been reserved for a comparatively small clientele, especially when it came to expansive systems with numerous components. This way of living out one’s passion for hi-fi seems to many people nowadays to be completely outdated and no longer in keeping with the times, this must unfortunately be admitted unreservedly.

Not least due to the fact that we live in a networked world in which PCs have long since been replaced by notebooks and in which smartphones, above all, represent the central component of the digital lifestyle, it is difficult to convey to a customer that he needs mountains of equipment for high-quality music reproduction. This is not necessarily a good thing, but it is unfortunately the case.

The frequently voiced assumption that consumers are no longer interested in high-quality music playback cannot be substantiated on closer analysis, but the enormous numbers of headphones sold worldwide, across almost all price categories, speak against this alone.

People who are prepared to spend a lot of money on headphones are naturally open to quality when it comes to listening in general, but you have to offer them solutions that correspond to their ideas, their lifestyle.

And that’s where concepts like the KEF LS50 Wireless II come into play, solutions that focus on the essentials, in every respect.

Active loudspeaker systems as the only component

You can’t do without high-quality loudspeaker systems, that’s very easy to make clear to every consumer in a convincing way. It is ideal, however, if this loudspeaker system is the only product needed for high-quality music enjoyment, and this is precisely the reason for the success of active loudspeaker systems from a wide variety of manufacturers in recent years.

And when they’re designed like the KEF LS50 Wireless II, there’s nothing standing in the way of a flexible hi-fi system, even at the highest level of quality.

The KEF LS50 Wireless II follows on from the KEF LS50 Wireless

The KEF LS50 Wireless II is, of course, based on its highly successful predecessor, the KEF LS50 Wireless, which was designed to be the only component in a hi-fi chain, but did not require the user to compromise on functionality.

In addition, and this must also be explicitly emphasised, the KEF LS50 Wireless was already based on the KEF LS50 compact passive loudspeaker system, which the English deliberately put in the reference class.

The new KEF LS50 Wireless II is based on the KEF LS50 Meta passive system, which has been drastically improved compared to the first generation. It’s clear that these innovative developments alone give the new KEF LS50 Wireless II an advantage over its predecessor, but the developers in Maidstone have also made further improvements to the electronics and the functionality and flexibility of the new KEF LS50 Wireless II.

KEF LS50 Wireless II – Everything you need…

To cut a long story short, the KEF LS50 Wireless II is a compact, yet very powerful active speaker system that offers a wide range of connections for a variety of sources, as well as streaming capabilities.

So it’s clear that the KEF LS50 Wireless II is designed in such a way that you don’t really need anything else besides this active speaker system, and probably even more consistently than its predecessor. Let’s see how this turns out in practice…

Compact and elegant

KEF’s designers have often demonstrated their ability to work hand in hand with engineers to create a concept that combines aesthetic appeal with the best possible conditions for optimum sound. In the case of the KEF LS50 Wireless II, Simon Davis and the KEF Industrial Design Team were primarily responsible for this, having already laid the foundations in the form of the KEF LS50 and KEF LS50 Wireless.

The new KEF LS50 Wireless II is an elegant, compact speaker system.

When we say compact, we mean a speaker system that measures 305 mm in height, 200 mm in width and 311 mm in depth. It’s all the more astonishing that you have to weigh a total of 20.1 kg when unpacking the KEF LS50 Wireless II and positioning it in its place.

You won’t find any hard edges on the KEF LS50 Wireless II, especially the baffle is curved and rounded at the corners. This not only looks good, it also ensures that the drivers have an optimal dispersion almost free of negative influences from the baffle, and that standing waves inside are prevented at the outset.

The interior construction is extremely complex, since not only the drivers and bass reflex system have to be accommodated here, but also the electronics. The electronics are located on the underside of the speakers, where the connection panel is also located. The rear panel is largely occupied by a cooling element that reflects the curved shape of the front.

The aforementioned bass reflex system is located on the back, offset outwards in the upper third of the speaker system.

The control panel in the form of sensor buttons is available on the front upper side of the right speaker, which should also be mentioned at this point.

Four appealing design variants

Particularly in this product family, as well as in the KEF Blade and KEF Blade II models, the English loudspeaker manufacturer makes skilful use of the possibilities offered by the special choice of materials and, not least, by the material of the driver diaphragms. Again and again, they present new design variants with successfully combined colours. The KEF LS50 Wireless II is available in four versions: Carbon Black, Titanium Grey and Mineral White. The Crimson Red Special Edition is also available.

All four versions feature a matte finish on the cabinet, while the cones of the loudspeaker drivers are presented in a copper, red or grey metallic look, each framed by a matte black surround. Incidentally, the colour of the diaphragm is picked up by the surround of the rear bass reflex tube.

KEF 12th generation Uni-Q chassis with MAT

The outstanding feature of the KEF LS50 II, and therefore the KEF LS50 Wireless II, is the latest generation of chassis from KEF. This is the 12th generation of the KEF Uni-Q chassis.

The KEF LS50 Wireless II’s 5.25-inch KEF Uni-Q chassis is actually a very exciting combination of high and low midrange drivers in a coaxial arrangement. In this way KEF manages to come very close to the ideal of a point source. The effort the engineers put into this can hardly be topped. There is probably no other driver design as complex as the KEF Uni-Q chassis.

With the 12th generation, all the essential features of the driver have been refined again, first and foremost a further optimised drive is now used, which is supposed to ensure even less distortion.

The most significant innovation in the KEF LS50 Wireless II, however, is the abbreviation that has been added to the driver: MAT.

MAT is a truly innovative concept that was first introduced with the KEF LS50 II and KEF LS50 Wireless II.

This abbreviation stands for Metamaterial Absorption Technology and was developed together with Acoustic Metamaterials Group. It essentially refers to an additional plate that is used behind the chassis and has a labyrinth structure that has been optimised in complex calculations.

In this structure, each of the complicated channels serves to absorb a specific frequency particularly efficiently. If you combine differently shaped channels, the construction based on this ultimately acts like an acoustic black hole, according to the manufacturer’s pictorial description.

This is intended to absorb sound emitted from the rear of the driver particularly effectively in order to guarantee optimally controlled reproduction at all times. This approach is so effective that an absorption of 99 percent is achieved compared to only about 60 percent with conventional systems.

This may seem like a small detail, but in fact it is an essential, truly innovative approach to making the imaging of the loudspeaker system more defined, clearer and ultimately more detailed. KEF’s talk of Metamaterial Absorption Technology as a revolution in loudspeaker design is therefore justified.

KEF Music Integrity Engine

When designing a powered loudspeaker system, you want to take advantage of all the benefits it offers, especially the signal processing, which is handled by the KEF LS50 Wireless II using the KEF Music Integrity Engine.

This is DSP-based and offers algorithms that have been optimised specifically for the KEF Uni-Q chassis. This is to ensure the best possible timing for an optimal soundstage.

Full power from Class A/B and Class D amplifiers

The KEF LS50 Wireless II also takes a very exciting approach to amplifier modules. They state that the optimum design was chosen for each driver.

For example, the tweeters are powered by Class A/B amplifier modules for a fine, detailed and silky sound with an output of 100 watts, while the low-midrange drivers are powered by particularly efficient and precise Class D amplifier modules with a whopping 280 watts.

If you break down the components in the KEF LS50 Wireless II, it’s actually a combination of a preamplifier with DSP-based signal processing, as well as power amplifiers designed separately for each driver, making a total of four mono blocks.

The amplifier modules were developed directly at KEF specifically for use in the KEF LS50 Wireless II, as the company states.

Connection diversity – everything there…

How flexible an active loudspeaker system actually is in practice is defined first and foremost by its connections. And the KEF LS50 Wireless II doesn’t give a damn about that, but rather offers everything your heart desires.

First of all, there is an analogue input called AUX, which is a 3.5 mm stereo mini-jack. In addition, there are two S/PDIF interfaces, one designed as an optical TOS link, the second variant as a coaxial S/PDIF.

But the most important feature of the KEF LS50 Wireless II is the HDMI input, which allows this active loudspeaker system to be connected directly to a TV. Of course, this supports eARC, the so-called enhanced Audio Return Channel, and HDMI CEC allows central control with the TV’s remote control.

While the optical S/PDIF interface can transmit signals with up to 24 bits and 96 kHz, the coaxial S/PDIF interface and the HDMI connection allow up to 24 bits and 192 kHz.

A subwoofer can be brought into play via an RCA connection, this should be mentioned at this point. Especially in larger rooms, the KEF LS50 Wireless II can be given even more sovereignty in the bass range, especially as KEF offers the new KEF KC62 Uni-Core Force Cancelling Subwoofer, a perfect extension for this active speaker system.

The USB port on the back of the speakers is for service purposes only.

Can it be wireless or would you prefer a cable?

What is new is that the two speakers of the system can now be connected not only by cable – a classic network cable with RJ45 connections is used here – but also by radio – true wireless. A proprietary wireless protocol is used, whereby all signals are resampled to 24-bit and 96 kH linear PCM.

Audio signals with 24 bit and 192 kHz linear PCM are transmitted via cable, which is also mentioned here for the sake of completeness.

Whatever you want… streaming in all its varieties

The KEF LS50 Wireless II uses the newly developed KEF Wireless Platform W2 to provide a full range of network streaming options. You can choose to connect the system via an Ethernet interface or the integrated WiFi module, depending on which option you prefer.

Once connected to the network, the KEF LS50 Wireless II serves as a dlna-certified UPnP streaming client, but also supports Google Chromecast and Apple AirPlay 2. This essentially provides the basis for using your own content as well as any available streaming service, regardless of whether you do this from a smartphone with Google Android or Apple iOS. The integration into Smart Home solutions is also ensured, this should be mentioned in passing.

KEF also offers a suitable app for the KEF LS50 Wireless II, the KEF Connect app for Apple iOS and Google Android. With this app, the functions of the active speaker system are directly available and it is also possible to access various streaming services.

The range of services includes Internet radio, podcasts, TIDAL including TIDAL Connect, Spotify including Spotify Connect, Deezer, Qobuz, Amazon Music and Apple Music.

In addition, the KEF LS50 Wireless II has long been designated as Roon-ready, meaning that it can be fully integrated into the media management and multi-room audio streaming solution from Roon Labs LLC. to allow bit-perfect streaming in a multi-room network with any other components.

When it comes to streaming, this solution supports audio data in Linear PCM format with up to 24 bits and 384 kHz, allows playback of DSD including DSD128 and is also equipped for content encoded in MQA.

Bluetooth is not missing

Although the focus is on streaming via the network, Bluetooth is not missing. For example, smartphones can be connected directly to the active speaker system as a source via Bluetooth 4.2, without having to integrate it into the network.

Convenient control

Of course, in most cases you will probably control the system directly via smartphone, be it with the app of a streaming provider or the KEF Connect app mentioned above.

As we have already mentioned, the speakers can also be controlled directly via a touch field.

You don’t have to do without a classic remote control either; when watching TV, the one on the TV set is enough. Nevertheless, the manufacturer also supplies a suitable infrared remote control with the KEF LS50 Wireless II, so you have all the options in this respect as well.

KEF S2 Floor Stand

Finally, there is one point we would like to address explicitly, and that is the best possible placement of the KEF LS50 Wireless II. In our experience, users who opt for a so-called bookshelf loudspeaker system, and this active loudspeaker system is nothing other than that, usually give little or no thought to the optimal placement of these loudspeaker systems. This is clearly a waste of the speaker’s potential.

Of course, in the simplest case, the KEF LS50 Wireless II can be placed on a piece of furniture, such as a lowboard or sideboard next to the TV. However, it is important to ensure that the speaker is decoupled so that as little energy as possible is transferred to the furniture, which can lead to a deterioration in precision. For the test, for example, we used the smart solution IsoAcoustics Aperta.

The best way to place such a speaker system in a room is clearly to use an appropriate stand, such as the KEF S2 stand KEF provides for the KEF LS50 Wireless II.

The KEF S2 stand features a top plate that provides secure mounting points for the speaker, precisely adjustable spikes with washers to protect the floor, and a hollow centre column that can be filled to ensure perfect sound. Also very important is an integrated cable management system, as this allows for a perfect presentation of the speaker.

From the practice

First of all, we have to state that we in the sempre-audio.at editorial team have been using a KEF LS50 for years. It is the crowning glory of a fine HiFi chain, which is built up with an Arcam CDS50 SACD/CD/Network Player and an Arcam SA30 Integrated Amplifier. And yes, we love this speaker, which demands a certain amount of power from the electronics, and is therefore by no means frugal, but then goes about its business in an extremely fine and sovereign manner. So it makes sense to put the KEF LS50 Wireless II right next to it and dare to make a direct comparison.

To get to the point: never, never do such a thing! Just don’t do it, because you will regret it.

They say old love never rusts, and yes, we loved our KEF LS50. So it was all the more painful when it was literally played into the ground by the KEF LS50 Wireless II. It was downright humiliating.

To put this into perspective, there is of course a certain amount of vanity on the part of a proud owner of the KEF LS50, but even soberly considered, the KEF LS50 Wireless II really is on a whole new level.

On the one hand, this is due to the fact that all the benefits of an active loudspeaker system are of course available here, where the designers can really fine-tune every component, as everything is in their hands.

On the other hand, KEF has, as promised, refined and improved everything in the new generation, especially the latest generation of KEF Uni-Q drivers with MAT.

On the one hand, it’s remarkable how confidently, accurately and powerfully the KEF LS50 Wireless II performs. The KEF Uni-Q driver with MAT finds exactly the power it needs for optimum results.

Based on this, it presents music with an almost playful ease, building up a remarkably wide, yet deep soundstage in front of the listener that is hard to escape, as sound sources can be located almost perfectly, but without tearing up the overall picture. Everything seems coherent, homogeneous and natural.

It was time to bring out the big guns, so the KEF LS50 Wireless II went into the next listening room and had to face the KEF Blade II.

All was right with the world again, because it can’t be that a new loudspeaker system, and a much more compact one at that, calls everything that exists into question. But when you think about what you have to budget for the KEF Blade II and the HiFi chain in front of it, and what the KEF LS50 Wireless II costs… You start to wonder because of the not-so-large distance.

Especially if the KEF LS50 Wireless II were to be fitted with a matching subwoofer, the advantage of its big sister would no longer be quite so glaring when it comes to rich levels down to the lowest frequencies, and if the listening room is not 80 m2 but more like a conventional living room, the KEF LS50 Wireless II might even have a clear advantage when it comes to discreet integration into the living room without having to accept too great a loss in the sovereignty of the performance.

And this is a point that, for us, clearly speaks in favour of solutions such as the KEF LS50 Wireless II, because, as already mentioned at the outset, for many users the time of expansive hi-fi castles is over; compact, powerful and equally versatile solutions are in demand. And the KEF LS50 Wireless II meets this demand perfectly.

The KEF LS50 Wireless II offers high-end hi-fi with all the intuitive possibilities of a networked world of consumer electronics in a particularly elegant form.

Getting to the point

The KEF LS50 Wireless II is a prime example of what modern high-end hi-fi looks like. Focused on the essentials of outstanding performance, coupled with the flexibility to access a wide range of sources and content, a compact form factor and an elegant design that is distinct and full of character, the KEF LS50 Wireless II can be easily integrated into any living space. Clearly, the KEF LS50 Wireless II is a reference in its class and comes with a clear recommendation.

The KEF LS50 Wireless II is an extremely flexible active loudspeaker system that offers all relevant connections, but above all streaming in all its forms. In addition, it presents music with an almost playful ease, building up a remarkably wide and at the same time deep sound stage in front of the listener, which is difficult to escape, as sound sources can be located almost perfectly, but without tearing up the overall picture. Everything seems coherent, homogeneous and natural.

Test environment

• NUCLEUS+ by Roon
• Samsung 65 Zoll TV
• TIDAL HiFi
• Apple iPhone
• Apple iPad
• IsoAcoustics Aperta