Wireless Multiroom Speaker Reviews

A modern recording like "Temptation," from Diana Krall's The Girl in the Other Room—another 'phile favorite"—sounded every bit as mesmerizing. The standup bass riffing in the opening bars was well back on the stage and sounded superbly natural, tightly defined, and woody, with plenty of extension. The riff ends on a B-flat sliding down a good fifth, reaching around 40Hz with no loss of presence or pitch. Impressive.

Full-orchestra, even at middle-of-the-house concert-hall levels, was just as satisfying. A recent recording of that old warhorse, Dvořák's Symphony No. 9 (Los Angeles Philharmonic/Dudamel, Deutsche Grammophon, MQA via Tidal) sounded fresh and exciting—even if Dudamel takes the finale too fast for my taste—with well-spread imaging and sparkling clarity. The clarinet solo about two minutes into that final movement was especially notable for gleaming liquidity, spaciousness, and musical seduction. (Most warhorses reach that status because they are, at bottom, truly great compositions. Exhibit A: Beethoven's Fifth.)

Which brings me to the subject of stereo imaging. The little KEFs performed the rare feat of getting out of the way of the recording engineer and producer. Studio tracks like the Jackson Browne song referenced earlier sounded close-in and spatially artificial (as expected), while live sessions like the Muddy Waters recording conveyed a believably "real" space. The same was true of close-in, live-style recordings like the Zemlinksy Quartet performing "String Quarter No. 2" (Qobuz) where the sound was arrestingly in-the-room. (If you want to hear what a classical/romantic tonal system disintegrating before your ears sounds like, you can't do better than this masterpiece.)

Like most coaxial designs—I believe KEF prefers "coincident"—the LSX II duo proved quite sensitive to placement and aim. As is the case with all horn-loaded tweeters—which is what a concentric design effectively is—the top few octaves are relatively directional because the tweeter's dispersion is shaped to a degree by the woofer cone within which it resides. Aiming the speakers directly at my listening position resulted in sound that was etched and noticeably brighter, while aiming them straight-on yielded a more natural timbral balance with a somewhat more diffuse, "spacey" presentation on material with lots of spatial cues.

I ultimately settled on cross-firing the KEFs with the sound converging on a point perhaps 18 inches in front of my head. This produced the treble balance I preferred and a stereo image that was consistently precise, stable, and convincing, even if it was a bit more confined and not as deep as what I had previously heard. The speakers' ability to project an instrument or voice to a specific soundstage location and hold it there, was very impressive and its ability to paint aural architectures was absolutely top shelf.

The Other Stuff
A few random points remain. First, about that "extra" Ethernet jack I mentioned earlier: the LSX II speakers, by default, link to one another wirelessly, and whatever program you feed them—regardless of source—is resampled to 24-bit/48kHz digital audio. But, if you hardwire the speakers to one another using an Ethernet cable and those extra jacks, resampling jumps to 24/96. I'm not too proud to admit that when I switched from wireless pairing to wired (and back), I failed to detect any difference, but hi-rez fanatics will likely prefer the latter, even if just on principle.

Getting back to the Phase Control option in the Connect app: turns out it compensates for the slight time-domain error introduced in the KEF's DSP crossover, realigning woofer and tweeter response to yield, at least in theory, perfect "step response"; only confirmed digital-audio geeks will know, or care, what that means. I spent a solid hour playing with this, turning it on and off in the app while auditioning various material. In this case, I believe I heard a difference with Phase Correction engaged, but it was so very slight and elusive that I hesitate to describe it, let alone state whether it sounded "better" or "worse." (If you put a gun to my head, I might admit that on some material, and only some, turning it on made midrange elements a shade clearer, or perhaps just barely more prominent.)

Next, a word for Roon-ies. KEF's marketing material describes the LSX II system as "Roon Ready," but an asterisk appends that certification is expected fall 2022. The feature was not in force during my audition period so the KEFs did not appear on my Roon page when connected via wired Ethernet, though they worked fine via "Roon Tested" Airplay 2.

Otherwise, day-to-day operation of the LSX II speaker system was a snap, whether streaming from the KEF Connect app or directly from the "native" Qobuz or Tidal apps on my iPad mini. (Though I confess this can get a bit confusing—which app is this, anyway?) Most users will be perfectly happy using KEF's app. It has all of the expected music-streaming features—playlists, "favorites," and the like—and is about as simple and intuitive as one can expect in this decidedly un-simple age. That said, I must observe that there are no physical controls on the LSX II speakers themselves apart from the pairing and reset buttons on the rear of the main speaker. So if the KEF remote—which provides volume, input, and play/pause/skip controls—is lost in the sofa cushions and your phone or tablet was forgotten at the office…

Lastly, the Connect app lacks any tone controls, per se. If you choose the "Expert" setup mode you can effectively adjust treble, midrange, and bass by a few dB each, but you must first dig deep into the 104-page PDF owner's manual to learn how these correlate to "Desk Mode," "Wall Mode," treble Trim, and Bass Extension; this is probably done by design to discourage ham-thumbed users from screwing up the LSX II's carefully created native balance.

Now, the little KEF does have a subwoofer output and built-in crossover, with controls available in the Connect app, so I had to take this for a spin. I jacked in my everyday sub—a compact, dual-8-inch design that's good to 25Hz and lower at any level I need in my room—and did a quick level and crossover setup, settling on 65Hz. The result was dramatic, just as you'd expect when you add a competent, carefully balanced sub to any set of small, band-limited speakers. The improvement was not so much in sonic character—the KEFs sounded just as clear, defined, and capable as they did without a sub—but gaining an extra octave-plus in extension and 10dB or so in useful level is transformational.

The sub-40Hz foundation in Donald Fagen's "Morph the Cat"—my go-to bass test—was fully intact with no loss in deep grunt or pitch. And when I revisited material like Dvořák's Ninth, I was able to enjoy front-row concert levels without sacrificing one iota of full-range dynamics. If you're eyeing a set of LSX II speakers for serious, audiophile listening at lifelike volumes, consider adding a suitable subwoofer. KEF's own excellent KC62 mini-sub (April/May 2021) is an easy recommendation but it is expensive.

Conclusion
Don't get me wrong, KEF's LSX II speakers are impressive and eminently listenable on their own and fully up to the task of reproducing almost any music, except perhaps the most challenging EDM or organ recordings. Even "just" on their own, they deliver exceptional sound quality and do everything almost anybody needs and almost everything anybody could desire.