EISA Award-Winner for Best High-End Loudspeaker Blends Performance, Technology, and Style: KEF R11 Tower Features Next-Gen Uni-Q Driver Array and Four Dedicated Woofers
Bestowed the prestigious EISA Award for Best High-End Loudspeaker by a consortium of more than three dozen international press outlets, the KEF R11 tower speaker combines cannot-look-away style, head-turning performance, and cutting-edge technology in a package certain to grab anyone's attention – and hold it for hours on end. From a technical standpoint, the three-way R11 includes five major innovations, mostly drawn from KEF's Reference Series, that extend from the advanced drivers to the beautiful cabinets. More importantly, R11 thrives in its role as a commanding tower model that conveys music and movies with exhilarating detail, clarity, and purity. Many speakers lay claim to the notion of "sounds as good as they look." With the 51 x 12.2 x 15.1-inch (HWD) R11, that statement isn't fantasy – it's truth.
In production for more than 30 years, the KEF Uni-Q driver – bundling a one-inch vented aluminum-dome tweeter with a five-inch aluminum-cone midrange – in R11 debuts in its 12th generation form. Its redesigned midrange motor system arrives courtesy of KEF's in-house simulation and analysis tools. Featuring a shaped and undercut pole as well as symmetrical aluminum demodulation rings that combine to significantly reduce the inductance in the lower midrange, the Uni-Q assembly both lessens distortion and enhances imaging.
Similarly effective, R11's Shadow Flare – a savvy method of diminishing cabinet diffraction – visually functions a trim ring while functionally serving as a surface that extends the Uni-Q waveguide effect. The tweeter no longer has line of sight of the cabinet edges, thus creating a shadow region at the points where the potential for diffraction remains highest, minimizing the acoustic impact to negligible levels. In sum, it provides a giant assist to the subtle cues and nuances in your favorite recordings.
Of course, R11 doesn't ignore the lower regions and provides deep, taut, punchy, and soulful bass. Four dedicated, 6.5-inch low-frequency drivers boast a redesigned magnet system and are built using a two-part structure, whereby a shallow concave aluminum skin sits atop a paper cone. The stiffness – combined with the cone's unique geometry – reduces additional resonances and delivers the pistonic movement that account for superb timing. Credit also goes to R11's flexible ports. Molded via computational fluid dynamics, the flare and profile of each port is calculated to delay the onset of turbulence all the while the walls prevent longitudinal resonances from coloring the midrange.
All the internal enhancements would mean less if KEF cut corners on the cabinet. Suffice it say nothing there got overlooked. R11 touts Constrained Layer Damping bracing in which the internal braces are joined to the panels by a lossy interface, helping to dissipate unwanted vibrations. In addition, a revised bracing layout furthers the creation of an inert platform that allows the drivers to operate at an optimal level. Color tone-matched aesthetics, optional microfiber magnetic grilles, and supplied spikes round out an 83.1-pound speaker ready for whatever you throw at it. 100% Music Direct Satisfaction Guaranteed.
"KEF has been making great speakers for almost 60 years, but it's hit a new high in style, performance, and value with the new R Series. The R11 brings together all the elements of that success, from the latest-generation coaxial Uni-Q driver for superb imaging and focus, anodized to match the choice of premium cabinet finishes, through to the clever micro-perforated grilles, which solve the old 'on or off' problem."
—EISA Award, Best High-End Loudspeaker 2019-2020
"[The] R11s deliver a sound that's both mature and rich, while at the same time airy and free-breathing, with a real impression of the orchestra before the listener. But above all that, what these speakers do is create an almost ridiculously easy listening experience. Whether I concentrated hard or just sat back and relaxed, the sound was equally impressive, and it's amazing how quickly I could accept what the R11s were doing as the norm, dial them out, and just get on with enjoying the music."
—James Parker, Hi-Fi News
"By design, the KEF R11 loudspeakers deliver a kind of purity or neutrality to the sound that can often reveal finer details that result in greater accuracy and realism – attributes that aren't found every day in more approachably priced speakers like these."
—The Absolute Sound
"The louder you wanted it, the better it sounded. They seemed to be limitless. As such I can imagine that they could readily be enjoyed with friends when entertaining, and cranked to 11 when listening to old rock anthems. On top of all of that, they also image incredibly well. The Uni-Q driver is responsible, and I can now understand what all the fuss is with this driver."
—Mark Gusew, Stereo.net
"The R11s provides a textbook-accurate frequency response, with punchy, extended, fast bass. Its midrange transparency and reproduction of detail are beyond reproach – always smooth, never edgy, yet not recessed. Nor was the R11's treble response ever etched or over-accentuated or sibilant, but always clear and extended. And their imaging abilities were outstanding for large floorstanders, equaling what my reference two-way mini monitors can do."
"It must be said, off the bat, that the new Uni-Q driver is something quite special. Here is a unique (pardon the pun) low-distortion design that has been refined to the point where, in this new iteration, it's capable of superb resolution, profound detail retrieval, overall smoothness, verisimilitude and astonishing soundfield rendering."
HF: 25mm (1in.) vented aluminum dome
MF: 125mm (5in.) aluminum cone
LF: 4 x 165mm (6.5in.) hybrid aluminum
Crossover frequency: 400Hz, 2.9kHz
Frequency range (-6dB): 30Hz - 50kHz
Typical in-room bass response (-6dB): 26Hz
Frequency response (±3dB): 46Hz - 28kHz
Harmonic distortion (90dB, 1m): <0.3% 0.3% 120Hz - 20kHz
Maximum output: 113dB
Amplifier power (recommended): 15 - 300W
Nominal Impedance: 8Ω (min.3.2Ω)
Sensitivity (2.83V/1m): 90dB
Without Plinth: 49.2" x 7.9" x 15.1"
With Plinth: 51" x 12.2" x 15.1"
Weight: 83.1 lbs.
User Manual (PDF, 6.4 MB)