The English specialist KEF is convinced that the so-called KEK Metamaterial Absorption Technology will trigger a true revolution in loudspeaker development. The first loudspeaker systems based on this technology are now being presented in the form of the second generation KEF LS50, the new KEF LS50 Meta.
It is certainly one of the most successful loudspeaker systems from the English loudspeaker specialist KEF, the compact solution of the reference class KEF LS50, which in its current form has been given many a new design over the past few years, but from a technical point of view has been available since 2011. This is a remarkably long time, and a clear indication that we have done some things right in the development process…
But now it’s time to take a new and, as KEF believes, huge step forward and introduce the KEF LS50 Meta, the new generation of this monitor speaker system. The basic design concept has been retained, and goes back many years beyond the KEF LS50’s 2011 launch, to the KEF LS35/5a, the BBC’s legendary reference monitor from the 1960s. Rather, it is a new technology that KEF believes will revolutionise the loudspeaker segment as a whole, and which is used in the KEF LS50 Meta, and is an essential basis for the 12th generation KEF Uni-Q chassis, known as KEF Metamaterial Absorption Technology.
Since the launch of the KEF LS50 in 2011, the company has continued to develop around a range of technologies, but KEF MAT is clearly a technological breakthrough, and this was achieved in conjunction with the Acoustic Metamaterials Group.
The new KEF LS50 Meta is the world’s first loudspeaker to incorporate this Metamaterials absorption technology, KEF said.
Once again, the lynchpin of the new KEF LS50 Meta is the so-called KEF Uni-Q driver, a design concept that comes closest to the ideal of a point source in the form of a coaxial driver arrangement, and which has been proven in virtually every product line in the UK for years. Now, as mentioned above, we have already reached the 12th generation of this driver design, which once again is intended to provide an even more detailed, accurate and almost three-dimensional sound image. The radiation is designed in such a way that the so-called sweet spot can be found almost everywhere in the room.
KEF has always seen itself as a technology-driven company, using the most modern approaches to development, such as simulation and analysis tools, in addition to the knowledge of its acoustic engineers, accumulated over decades.
The 12th generation of KEF’s Uni-Q chassis, for example, features a new cone neck decoupler and a new drive system that is precisely shaped to reduce distortion in the midrange tweeter. The result is less colouration, less distortion and a sound that is more transparent and lifelike than previously possible. The same could be said of the bass performance, according to KEF, the new KEF LS50 Meta also exceeds the expectations of a modestly proportioned bookshelf speaker in this respect, delivering a room-filling sound with deep, articulate bass.
The most spectacular innovation, of course, is KEF Metamaterial Absorption Technology, which ultimately describes a disc of synthetic material with a highly complex labyrinthine structure used at the rear of the driver. In this structure, each of the complicated channels serves to absorb a particular frequency particularly efficiently. If you combine differently shaped channels, the construction based on this structure ultimately acts like an acoustic black hole, according to the manufacturer’s pictorial description, because 99 percent of the unwanted sound waves coming from the back of the driver are absorbed. This means that there is no way that these could affect the reproduction of the entire KEF Uni-Q driver, guaranteeing a particularly pure, natural sound.
An optimised bass reflex system was already an essential part of the design principle of the previous KEF LS50, along with the KEF Uni-Q driver, and this is of course also the case with the new KEF LS50 Meta. The manufacturer refers to this as a special port design, developed and optimised using Computer Fluid Dynamics, or CFD for short. This resulted in a very special expansion and flow-optimised profile. But not only the design of the port is decisive, it is also positioned asymmetrically to the chassis.
This effectively prevents turbulence and flexible port walls also serve to eliminate resonances that discolour the midrange. This also leads to improved clarity with exceptional depth and detail, according to the manufacturer’s description.
The KEF LS50’s unusual cabinet design was already noticeable on the previous KEF LS50, and is the basis for the new KEF L50 Meta. It is an extremely rigid case, developed using finite element analysis and optimised for best performance. Once again, the emphasis is on smooth, curved surfaces. First and foremost, the baffle is precisely modelled around the KEF Uni-Q driver. The curved structure is designed to ensure that sound is radiated through the baffle without interference. Inside, too, a very robust construction is used, based on cross-bracing and so-called CLD, i.e. Constrained Layer Damping, so that vibrations are largely eliminated. According to KEF, this is another key factor in achieving the promised very low sound colouration of the KEF LS50 Meta. The gently rounded rear panel reflects the curved front and now features recessed connection terminals.
The KEF LS50 Meta’s special cabinet naturally allows designers plenty of scope, especially when combined with the KEF Uni-Q driver with its aluminium cone. The KEF LS50 has been available in a variety of colour combinations, and the new KEF LS50 Meta continues this tradition. This loudspeaker system is available in Carbon Black, Titanium Grey, Mineral White and a Royal Blue special edition.
The KEF LS50 Meta is a two-way bass-reflex speaker system that combines a 25mm vented aluminium dome, equipped with Metamaterial Absorption Technology, with a 130mm low-midrange driver, which also uses an aluminium cone. In conjunction with the rear-facing bass reflex system, this should enable a frequency range between 47 Hz and 45 kHz to be reproduced, with the crossover network starting at 2.1 kHz. With an impedance of 8 ohms and an efficiency of 85 dB, this loudspeaker system is designed for amplifiers with a power output between 40 and 100 watts.
The new KEF LS50 Meta measures 305 x 200 x 311 mm, making it 7.8 kg.
It is interesting to note that KEF now has matching speaker stands available for the launch of the new KEF LS50 Meta, in the form of the KEF S2 Floor Stand.
The KEF LS50 Meta has a thread on the underside of each corner so that the speaker snaps securely onto the base of the KEF S2 Floor Stand. Of course, the stand has integrated cable management and is designed as a very robust column.
The new KEF LS50 Meta is expected to be available at the recommended retail price of €1,199 from specialist retailers, as described above. The choice is between Carbon Black Titanium Grey, Mineral White and the special edition Royal Blue.
Getting to the point
Even though the KEF LS50 has been a hugely successful product in the marketplace for years, it is now time to take a new and, as KEF believes, huge step forward by introducing the KEF LS50 Meta, the new generation of this monitor speaker system. The basic design concept has not been shaken, as it goes back many years beyond the KEF LS50’s launch in 2011, to the KEF LS35/5a, the BBC’s legendary reference monitor from the 1960s. Rather, it is a new technology that KEF believes will revolutionise the loudspeaker segment as a whole, and which is used in the KEF LS50 Meta, and is an essential basis for the 12th generation KEF Uni-Q chassis, known as KEF Metamaterial Absorption Technology.