Flagship three-way floorstander
The largest model in the R Series combines four bass drivers and the latest generation Uni-Q for a powerful and refined sound With hybrid aluminium bass drivers and a 12th generation Uni-Q for mid and treble the mighty R11is extremely capable. Using technology from KEF Reference it delivers clarity, finesse and serious bass.
The R Series
R Series offers a choice of three floorstanding speakers, a stand mount for more compact spaces and accompanying matching theatre models. Each one offers the finest sound KEF has ever delivered in its category whatever the dimensions of the room or system configuration.
R Starts with Reference
At KEF the Reference Series is the home of cutting-edge technological innovation. This is the result of diligent, creative research and development by the very best engineers in the business. The new R Series benefits from many of the technologies, materials and developments created for the Reference Series.
Feel the Music
When you want to forget the world and simply lose yourself in sound, R Series will take you there. At KEF, the quest to develop perfect loudspeakers has lasted more than 50 years. Like you, we don’t just want to hear music; we want to experience it, get inside it and feel part of it.
Sound is the Real Story
In the movie world, the best sound engineers are capable of weaving ever more wonderful sonic webs and the new R Series is your ticket for getting the best out of movies, delivering the natural, consistent sound essential for a phenomenal surround sound experience.
Beautiful by Design
Form follows function in KEF loudspeakers, so while the R Series is driven by acoustics all fixings are hidden, so all you see is a beautiful, clean exterior. The R Series comes in two sleek gloss finishes or a classic wood veneer and KEF’s tone-on-tone style means that the details are colour-matched to the finish.
The R Series was created to sound its best with or without grilles. The microfibre grille design is a first for KEF and not only looks beautiful but has a negligible effect on performance. They continue the tone-on-tone approach to match the various cabinet finishes and the edges are burnished for a suede-like effect.
The evolution of KEF's Uni-Q driver reaches its 12th generation in the R Series. Using simulation and analysis tools KEF’s engineers have been able to dramatically reduce colouration by cutting resonance in the tiny gaps between Uni-Q’s elements. The result is purer and more precise sound with stronger imaging.
The Shadow Flare is an innovative way to cut harmful high frequency cabinet diffraction. It's a carefully profiled transition that extends the waveguide effect of Uni-Q. The treble escapes naturally because the ‘shadow region’ stops it getting to the cabinet edges. The result is vastly improved fine detail.
Low Frequency Drivers
R Series bass drivers have a two-part structure with a shallow concave aluminium skin atop a paper cone. Combine this stiffness with the cone’s unique geometry and you get near pistonic movement for punch and speed. KEF has also increased linearity in the magnet system which means more impressive and impactful bass.
Flexible Port Technology
When it comes to generating deep, articulate bass, port design is crucial. The R Series ports have innovative flexible walls. Using computational fluid dynamics the flare and profile of each port is calculated to delay the onset of turbulence and the flexible port walls prevent resonances from colouring the midrange.
A solid platform is imperative for great sound. The new R Series benefits from Constrained layer damping. This system utilises internal braces joined by a ‘lossy’ interface and is highly effective at dissipating unwanted vibrations that would otherwise artificially change the sound and music.
Weight: 37.7 kg
Dimensions (HxWxD): 1295.5 x 310.6 x 383.5 mm (with terminal and plinth)
Design: Three-way bass reflex
Frequency Range: 30Hz-50kHz (-6dB)
Typical In-Room Bass response: 26Hz (-6dB)
Frequency Response: 46Hz-28kHz (±3dB)
Harmonic Distortion: <0.3% 120Hz-20kHz (90dB, 1m)
Maximum Output: 113dB
Amplifier Power: 15-300W (recommended)
Nominal Impedance: 8 Ohms (min.3.2Ohms) Drive Units: HF: 25mm (1in.) vented aluminium dome; MF: 125mm (5in.) aluminium cone; LF: 4x 165mm (6.5in.) hybrid aluminium
Crossover Frequencies: 400Hz, 2.9kHz
Finishes: Black Gloss / White Gloss / Walnut