KEF R11 Loudspeaker

Beauty and Intelligent Design

Equipment report
KEF R11 Loudspeaker

As any hi-fi enthusiast knows, there’s no shortage of attractive loudspeakers out there nowadays. But beauty only goes so far if the sound isn’t up to snuff. Happily the KEF R11, the flagship of the venerable British marque’s mid-tier R series, delivers smart technology for great sound in a pretty package—and for less dough that you might expect. 

Positioned above the entry Q series and below the Reference series, the R series was first launched in 2011 but is now in its fresh 2018 iteration. For the latest models, a new motor system, cone, and surround have been added to the midrange driver in KEF’s signature Uni-Q coaxial array. In addition, a new proprietary technology has been developed to control acoustics at the tweeter and midrange junction of the coaxial driver. According to a white paper from KEF, these redesigns are intended to deliver cleaner sound with less distortion and coloration.

And based on the time they’ve spent in my listening room, I’d have to say that the R11s achieve these goals to a large extent. 

A three-way, bass-reflex floorstander, the $5k-per-pair R11 contains the same size Uni-Q concentric array (5" midrange with 1" vented aluminum dome tweeter) found in the Reference and Blade speakers; it also has a Tangerine waveguide to improve high-frequency dispersion. This latest version of the Uni-Q coaxial array is surrounded by a “shadow flare” trim ring, which extends the waveguide effect. According to KEF, “the tweeter no longer has line of sight of the cabinet edges, creating a ‘shadow region’ at the points where the potential for diffraction is highest, minimizing the acoustic impact [of the enclosure] to negligible levels,” and helping to prevent the “scattering” of soundwaves that diffract on the baffle’s edge for clearer, more accurate sound. 

Now in its twelfth version, the unique Uni-Q point-source has long been the gem in KEF’s crown—or in this case, its literal centerpiece: In this D’Appolito configuration it’s nestled between four 6.5" aluminum (hybrid with paper) woofers, two above the Uni-Q and two below. The Uni-Q driver array is identified by name in small grey letters on the front panel. The speaker also bears the KEF logo at the top of the MDF cabinet’s front—in silvery-grey lettering on my white review samples. Sleek and modern in style, the R11 is available in three finish options: white or black gloss with tone-on-tone diaphragms, or walnut wood veneer with rose-gold-colored diaphragms. 

Returning to not-so-desirable types of coloration—the sonic kind—another way in which KEF has reduced cabinet resonances is through reworking the enclosure’s internal bracing layout, structure, and damping system, rendering the box more inert and thereby helping to minimize coloration for a purer, more neutral presentation. KEF makes its own enclosures as well as drivers, which allows for greater design flexibility, innovation, and ultimately more options for customers. 

Before I talk about these R11s, what I’ve noticed and come to associate with KEFs, from the compact LS50 Wireless to the big Blades and flagship Muons (which I’ve auditioned at different shows), is their ability to disperse the sound smoothly and non-aggressively, while also delivering solid lower-octave heft. When reviewing the li’l LS50 Wireless I was delighted by that compact’s broad dispersion and the unexpected amount of bass it managed to produce. Yet with the R11s, coherence and clarity stood out first, although the speakers still delivered wide and smooth dispersion. No doubt the concentric Uni-Q driver reinforces this clear, coherent delivery, and based on my critical listening time, the latest version apparently prioritizes and refines this attribute. However, given the number of woofers I’d anticipated some subtle coloration, more of a “bottom-up” sound, than I actually heard. That’s not to say the R11s shied away from bass; they didn’t. The woofers were quite linear and deep-reaching, and the pair of ports on the rear of the speaker enclosures seem to augment their low-end expressiveness without any huffing or puffing. Nonetheless, the R11s struck me as more neutral to “top-down”-sounding in character than what I’d expected given all those bass drivers, and I’ll admit that certain genres of music might have benefited from a bit more bottom octave slam, though I never really felt the urge to add subs.