KEF LSX Review: The perfect All-in-one speaker

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If the task is to have speakers, an amplifier, a DAC, a streamer, a bluetooth – and all this at the Hi-Fi level in one small box, or rather two, then the list of such systems on the market is small. It is worth removing the word Hi-Fi from the list of requirements, then the list becomes more than long, but we really need Hi-Fi, right? If yes, then read on.

KEF LSX
KEF LSX

Short background. Once upon a time, a long time ago , KEF released the KEF LS50 which was very popular, then after almost 6 years they decided to make it wireless and everything is fine, premiums, delights and high ratings, but! The price of the LS50 Wireless , and then the size, reduced the list of potential buyers. The company felt that people needed something more compact and cheaper, so they decided to expand the range and make the younger version cheaper and smaller, this is the hero, or the heroine of our ballad – KEF LSX .

Secretly, KEF LSX wireless speakers are actually like wired ones, because they are not powered by sunlight and do not have batteries inside. Whether you like it or not, you need to have two sockets on hand from which two massive cables will go, emphasizing your “wireless”. This little nuance is worth bearing in mind. Too bad, they look damn good without wires. On the other hand, I have yet to see a battery powered Hi-Fi.

Specifications KEF LSX:

  • HF driver: 19mm aluminum dome
  • Mid/bass driver: 115mm aluminum magnesium annular cone
  • Frequency response: 49Hz – 47kHz
  • Amplifier power: LF/MF – 70 W, HF – 30 W
  • Maximum sound pressure: 102 dB
  • Connectivity: Optical input, Aux 3.5mm, RJ45 Ethernet, Bluetooth 4.2, Wi-Fi 2.4/5GHz
  • Outputs: RCA subwoofer
  • Supported Bluetooth codecs: SBC, AAC, aptX
  • Maximum audio resolution: 24bit/192kHz
  • Support for third party services: AirPlay 2, Roon, Spotify Connect, Tidal
  • Dimensions: 240×155×180 mm
  • Weight (left/right): 3.5 / 3.6 kg

The speakers were designed by Michael Young himself, whom I suppose few people know about, I myself have never heard of either. The speakers look a little futuristic if you imagine that we are a hundred years ago. And jokes aside, the front is made of matte plastic (I don’t really know what kind of material it is, but it looks like plastic), the sides, top and bottom are wrapped in fabric. The back side is also made of plastic. At the back there is a phase inverter and a panel for control and connection. Right at the first hit of the speakers in the hands one feels the quality, considering the details closely, the speakers produce extremely positive emotions. From the looks of it, I’d say the LSXs look more like bluetooth speakers than hi-fi. If we talk about the design in general, then I think they are more suitable for a modern interior.

KEF LSX
KEF LSX

Speakers are available in five colors: black, white, blue, burgundy and olive. I got the black version, which in my opinion is the most classic and versatile. It is worth noting that the olive version has the “legendary” autograph of the creator on the front side, but the white version is lacquered and, unlike the others, is not wrapped in fabric. By the way, the fabric is made by the Danish company Kvadrat, for me personally, as well as probably for you, this does not mean anything, you just need to know that it is of very high quality and looks decent. In general, the build quality is excellent, nothing to complain about. A highlight in proportions and small details.

KEF LSX are very compact and I think there is a place for them anywhere. They can be placed on a chest of drawers, a bookcase, a small work table or even a refrigerator to listen to high-quality Hi-Fi while you cook. But their weight is decent, in appearance they seem much lighter, a home-made chest of drawers made of plywood can bend.

As for connections, I want to highlight the presence of RCA for the subwoofer. You can connect any active subwoofer, which, in my opinion, is a very smart move. Unlike most stationary amplifiers that have this output, the LSX outputs a weaker signal to the subwoofer, in my case this was not a problem. Also a nice bonus on the rear panel is the presence of USB A as a power source.

Functionality

I think that the price of KEF LSX is formed to a greater extent by its electronic filling and only then by the sound. Maybe I’ll guess if I say that 40% of their cost is electronics and wireless technologies. The speakers are interesting in terms of functionality, they can work as a full-fledged streamer with Tidal and Spotify, they also have Bluetooth and AirPlay 2, and it’s worth mentioning separately the KEF Control application, which has a lot of interesting “chips”, about them a little later.

LSX can work wirelessly with each other (meaning communication between speakers), for this they need to be paired, or they can be connected using an RJ45 cable (supplied with speakers). It is worth noting that in the case of connecting the speakers to each other “over the air” via Wi-Fi 2.4GHz, they are capable of reproducing a signal with a resolution of up to 24 bit / 48 kHz,

KEF LSX
KEF LSX

Now in more detail about streaming technologies. Unfortunately, I was unable to test Tidal and Roon as I don’t have a subscription, but Spotify, which I have been using for many years, in particular Spotify Connect, works great. Fast connection, fast response. Was it worth expecting another? The way Spotify Connect works on the LSX is not much different from how it works on any other device. You press the “devices” button in the Spotify app, and it immediately displays the speakers in the list, by clicking on them, the connection is instant, on the LSX it works like iron.

As for Bluetooth, things are a little worse. The connection is not always fast and smooth, and the stable reception distance turned out to be a little less than the speakers for $150. Even when the speakers are connected via Bluetooth and there is no signal, you can hear a high-frequency squeak and noise in addition to background noise from the amplifier, which in my opinion is extremely strange considering the price tag.

In general, I can say that Bluetooth is more or less adequate for both Apple and Android. On Apple technology, it is traditional to transmit Bluetooth in AAC format, for the rest it is mainly aptX or SBC. aptX HD format is not supported. Speakers play through the “blue tooth” noticeably worse than through all other modes. AirPlay 2 is available to owners of Apple technology, and here it works perfectly. The sound while watching the video is perfectly synchronized with the picture.

For me, the most interesting was the KEF Control application. I want to say that the speakers work perfectly without any applications, using the KEF Control application is optional. If you are a happy owner of LSX speakers, then in my opinion it would be very stupid not to use this application.

Unfortunately, the application is very buggy and has a lot of problems. At first I thought that the problem is individual, but it turned out that the application has an extremely low rating on both Apple and Android. It’s a pity, because many proprietary technologies are based on working with the application. So, after installing and first setting up the application, we have access to numerous “chips” for fine-tuning the speakers. Perhaps I will skip most of them and describe only what interested me the most.

Namely KEF Audio Signature, which has two setting modes “Basic” and “Expert”. In a couple of minutes in Basic mode, this option allows you to adjust the speakers depending on their position. I tried changing the position of the speakers and then their settings, in most cases the settings helped to improve the sound a little, especially to reduce the boominess and improve the stereo panorama a little. Separately, there are subwoofer settings and even a digital crossover. Also, the application allows you to configure many settings such as connection type, volume control, balance, etc.

Unfortunately, I did not find a banal equalizer in the application, I think it would be very appropriate there. In general, I can’t say that I found a huge benefit in the application, but I managed to improve the sound a little. I tried changing the position of the speakers and then their settings, in most cases the settings helped to improve the sound a little, especially to reduce the boominess and improve the stereo panorama a little.

Separately, there are subwoofer settings and even a digital crossover. Also, the application allows you to configure many settings such as connection type, volume control, balance, etc. Unfortunately, I did not find a banal equalizer in the application, I think it would be very appropriate there. In general, I can’t say that I found a huge benefit in the application, but I managed to improve the sound a little. Also, the application allows you to configure many settings such as connection type, volume control, balance, etc. Unfortunately, I did not find a banal equalizer in the application, I think it would be very appropriate there. In general, I can’t say that I found a huge benefit in the application, but I managed to improve the sound a little.

The KEF Stream app is also available for working with speakers. I can’t say much about it because I haven’t installed it. But in short, this is a proprietary player that allows you to play music and connect streaming services. Now about the sound itself.

Sound

The speakers inherited the Uni-Q driver, the tweeter is located in the center of it. Interestingly, the first Uni-Q driver was developed back in 1988, LSX uses the 12th generation of this driver. The tweeter is an aluminum dome with a diameter of 19 mm, and the midrange and bass are an annular diffuser made of aluminum-magnesium alloy with a diameter of 115 mm. As conceived by the developers, this solution eliminates problems with phase distortions. In general, the speakers are close in characteristics to their sister LS50, although they sound differently. Now in more detail about the sound.

Let me remind you that these speakers are small, so that they can be put in a chest of drawers. Before turning on these speakers, I expected to hear a sound that corresponds to their size, as we are used to – there is no bass, the middle and top are yelling, porridge is playing. Everything is different here. The first thing you pay attention to is the bass, it is here and it is in abundance. Especially if the speakers are against the wall, in this position, in my opinion, they definitely do not need a subwoofer. The wall reflects the sound wave coming from the phase inverter and then the bass is able to surprise with its impact and weight. Speaking of bass, for comparison, the Adam T7V studio monitors that I have at hand have as much bass as the LSX, but the small nuance is that the Adams are three times more. At the same time, the quality of this bass is not worse than that of KEF.

MF and HF range to my ear is quite linear. The key word that describes the sound of midrange and treble is comfortable. Nothing screams or cuts the ear. The highs are a little smoothed out, they lack realism and sharpness, some recordings may lack sharpness. I also note a good level of detail over the entire range, and this is not an illusion of clarity due to raised treble, as it happens. An interesting feature of the speakers when watching a movie is that in moments of action they seem to turn on their reserve, especially for twitter and breaking glass sounds extremely realistic. That is, the cups are able to play music with exemplary naturalness and immediately demonstrate speed, dynamics and sharpness while watching a movie, while completely doing without a subwoofer.

The ability to transfer space from the speakers is at a good level, and given the size, it is excellent. The speakers, yes, do an excellent job with recordings with a medium and small number of instruments and details. LSX in the correct position, and especially if not near the walls, recreate the scene well with all the nuances thanks to the technology embedded in them.

I think the strengths of the speakers are the scene they are able to recreate, organicity and “wholeness”. The merit of the combined midrange driver with a tweeter – Uni-Q in the disclosure of the sound stage, as well as the organic sound. According to the manufacturer, the problem of time synchronization was solved precisely thanks to this placement – the tweeter is in the center of the midrange driver. In addition to this, the DSP (Digital Signal Processor) removes the phase shift between the frequencies that have been processed by the crossover. Thus, the speakers are capable, if not surprising, then demonstrating really considerable abilities.

KEF LSX
KEF LSX

To sum up, KEF LSX are relatively versatile, but with their sound style they are more suitable for those who are not looking for sharpness, but appreciate naturalness, organicity and the ability to convey space. The speakers lend themselves well to the equalizer, they have a large supply of both bass and treble. Despite the fact that there is a subwoofer output on the rear panel, and it can be fine-tuned in the application, I never wanted to connect it, in music I did not feel a lack of bass. Perhaps the exception would be cinema, here sometimes there was not enough “weight”.

Comparisons

I have noticed that the LSX plays best at volumes closer to 40%, while the Dali system does not have this feature and plays more or less normally at much lower volumes. Therefore, setting the volume as close as possible on both systems to 40% of the KEF volume, I heard the following – bass, the Kefs have much more of it, and it goes lower.

The manner of sounding kefs is smoother and more linear throughout the entire range, it seemed to me that live instruments play more naturally and corporally. It also catches the ear that the kefs play as if everything is somewhere there, in the next room (this is only audible in close comparison). Kef trebles are softer, on many recordings there was a feeling of slight haze due to their restraint. The weaker bass and brighter highs of the Dali created a feeling of more airiness and detail.

The stage construction is good on both systems, the biggest difference is that the kefs sound “there” and the distances sound “here”. For dali, the sound is spatially much closer and at the same time much flatter, while for kefs it is farther and much more voluminous. On kefs it was a little easier for me to “see” where the instruments and the singer are, everything is a little better drawn in space. Both systems reproduce vocals perfectly, the comparison is complicated by the fact that on one record the vocals sound better at a distance, on the other record the vocals sound better at kef. Regarding the voice – sometimes there was a nasal feeling on the kefs, if you know the expression “sings or speaks through the nose”, also as if the voice passes through a dense fabric, while Dali never noticed this.

The overall sound is more comfortable on the kef mainly due to the softer highs. It is very important to note that a subwoofer is needed for distance, not for kefs. Therefore, if you buy a subwoofer, then KEF immediately wins for the price.

So, in the end, to my ears, Dali win a little in treble and lose in the ability to transmit the scene, they also lose in the amount of bass. KEF definitely wins in recreating the scene. Dali sound more bright, airy and closer to the listener. The KEFs are more linear in the mid and high ranges, but the lows are raised and emphasized, making the speakers prone to being boomy in an unprepared room.

It’s very difficult to say which system I like best by sound, it depends a lot on the record. The ability to create depth and three-dimensionality is unmatched by kefs. The downside of the Dali system is that it requires a subwoofer, and adding in how much space it takes and how many wires in a Dali system, I think KEF speakers win instantly.

Remarks

A few notes that it will be useful for a potential buyer to know. Unfortunately, it was not possible to avoid lags. The KEF Control application, which, despite a large number of updates, lags decently, the problems were numerous and completely different, both on Apple and on Android devices. I do not rule out that I did something wrong. I also had a situation once when the second column was “lost” and stuttered for an unknown reason, during settings changes in the KEF Control application. The RJ45 wire helped bring the second speaker back to life. The speakers emit a slight background noise, just like budget active acoustics do. The work of Bluetooth causes some complaints. It is impossible to turn on the speakers without a remote control or an application and often you need to wait 10 – 20 seconds when turning it on.

KEF LSX
KEF LSX

As you know, almost all acoustics tend to sound worse at low volumes, this is due to many factors both from the technical side and from the anatomy of the ear. If we talk about technology, then there are systems that suffer from this more, some less. In LSX, unfortunately, this effect is more pronounced, they play frankly muddy at low volume, closer to 35% volume they “open up”. For the first three days I listened to them at a volume below 20% – there was a feeling that somewhere there were incorrect settings or it’s a frankly unsuccessful model.At this volume, the tweeters are smeared and dropped down, the speakers swallow the details and cannot transmit the scene.At the same time, at half the volume they play just fine, at the maximum of their abilities.

Conclusion

Despite all the nuances associated with electronics, KEF LSX sound good and can compete with models almost three times larger. KEF has shown that in such a small size it is possible to create, if not ideal, then a good multifunctional system, which, from the example described above, can compete with a full-fledged heavy, passive Hi-FI system. Yes, the price is not small, but it is very difficult to find such a system in this size. It is worth emphasizing that LSX has an exceptional ability to convey volume and three-dimensionality. Before KEF fell into my hands, I was sure in advance that the speakers were not worth half of their price, now I understand that this is not so, the price is justified by the sum of the qualities embedded in the speakers.

To sum up, the LSX is an interesting multifunctional system for music and cinema, an all-in-one Hi-Fi solution that does not require much space. As for alternatives, I personally can’t name any competitors or just don’t know any. So if you are looking for a good wireless and compact  hi-fi audio system  with good build quality and great design, then you should pay attention to the KEF LSX.