The KEF LS50 Wireless II ranks high in the rarefied world of ultra-high-performance compact wireless speakers. With its meticulously detailed, taut and true sound and KEF’s long history of building mini monitors, this little web-connected stereo pair should find favor in the control rooms of streaming subscription services, broadcast stations, and radio stations. online radio and podcasters to measure the quality of your network signals.
But I feel like the most receptive audience for speakers will be wealthy audiophiles, reducers, and clutter advocates whose appetite for sonic excellence now far exceeds their available space for stacks of hifi equipment and physical albums.
And while KEF speakers have a reputation for being demanding in terms of their power requirements, the onboard amperage driving this show far exceeds the challenge. It should, too, given the main price of the set: $ 2,799.99 for the pair.
Setup and operation are straightforward, with gorgeous (and surprisingly simple) fine-tuning involved. In Easy mode first introduced to the user (there is also an Expert option revealed in KEF Online User Manual), the KEF Connect app simply asks you to indicate the size and reverberant nature of the room where the speakers are placed, as well as where will be placed in the room. The application then applies digital signal processing to adjust the bass and treble appropriately. Add a KEF subwoofer, such as the powerful, 10-inch, 300-watt Kube 10b ($ 750) I also auditioned, and the KEF Connect app will optimize the trio’s crossover frequency as well.
The good news is that wherever you drop them, these stylish things are sure to dress up the neighborhood. Note the shapely two-tone face, the slim but deep dimensions of 12 x 7.9 x 12.2 inches (HxWxD), and the equally attractive rear panel with its matching color port and stylish integrated heat sink. . Small but heavy at 22 pounds each, these beauties even come in a variety of color combinations to match your interior décor in your home.
Specifications, Features, and Design Notes
KEF calls their two-in-one speaker setup Uni-Q, and it’s the secret sauce that brings their sound together like no other. Unlike old school, the space-saving two-in-one coaxial speakers where the tweeter “floats” in a separate speaker-like enclosure in front of the woofer, the low-frequency (LF) and high-frequency (HF) drivers in a Uni-Q arrays are fully integrated to function as a single point source. The woofer cone even does double duty as a waveguide, helping smooth dispersion and integration of the neutral-centered tweeter output.
Now in his 12th generation, Uni-Q has gained a maze-like frequency filtering system called Metamaterial Absorption Technology (MAT) that connects to the back of the tweeter and absorbs 99 percent of the return wave energy from 600Hz upwards, which can cause loss of time. distortion.
KEF installed Class D amplifiers in each speaker driving the 5.25-inch aluminum composite woofer / midrange driver with 280 watts of power and Class AB amplifiers to drive the perfectly seated 1-inch vented aluminum dome tweeters. in the center of the woofers.
The LS50 Wireless II are premium, expensive luxury items that reward the most discerning listener with a richly detailed sonic view of the world. With a frequency response of 45Hz to 47kHZ +/- 3dB (that’s before Add a sub!), They are everything you would crave for music and TV sound in a smaller living room or studio, where the tight articulation of the low frequency driver and the pumping of air from the well-tempered rear port can make you the bass The answer seems quite palpable. In a larger room, you’ll be happier with a connected subwoofer that adds another octave of low-frequency depth.
Suitable for speakers that offer high frequencies detectable only by aliens (I’m kidding, mostly), these things can process digital files with a resolution of up to 24 bits and with sample rates of up to 348 kHz over a network connection ( both MQA and DSD56 files supported), 24/96 via digital optical connection and 24/192 via digital coaxial or HDMI eARC.
Use the speakers connected wirelessly to each other and all sources will be resampled at 24/96 PCM. Connect the speakers together with an Ethernet cable and all sources will be resampled to 24/192 PCM.
You can also stream music from all the most popular services, including Amazon Music (which just announced support for Amazon’s HD and Ultra HD tracks), Deezer, Qobuz, Spotify, and Tidal. The speakers are also compatible with the Spotify Connect and Tidal Connect apps. There is also support for Apple AirPlay 2 and Chromecast, and the system is ready to boot. You can use Bluetooth if you want, but support is limited to Bluetooth 4.2 and there is no support for aptX. Apple Music support, however, is curiously absent.
I found the KEF LS 50 Wireless II especially revealing and rewarding when streaming high-resolution (CD-quality) and even ultra-high-resolution (SACD-, DVD-Audio- and Blu-Ray Audio) live recordings. Naturalistic voice and acoustic instrumentation, barely processed. With eyes closed, the original recording of the cast of Lin-Manuel Miranda Hamilton it really put me in “the room where it happened”.
I’d say the high-resolution sonorities of Hiromi Uehara’s new fusion of jazz and classical Silver Lining Suite adds a good 20 percent to its charm, due to the pristine 24-bit / 192 kHz encoding (transmitted via Qobuz) and the vivid rendering of the KEF speakers of your Yamaha concert mates and violin, viola, and cello. Equally revealing were the 24/96 broadcasts of Donald Fagen’s two new concert releases:The Nightfly: Live and Steely Dan’s set Northeast corridors, as well as a raucous Montreux festival set by Van Morrison and company attached to the 2019 Deluxe Edition of The healing game. What a pretty surprise!
I have also greatly enjoyed exploiting these speakers as near-field monitors, reclining between the speakers in a flashback to my lost youth; more appropriately with the new Let it be box set that greatly expands on The Beatles’ least-produced late-period album. The LS50 Wireless II provided an aural experience of flying on the studio wall, and what a journey it is to hear scaled-down, remixed, and radically different work-in-progress performances of tunes like Return, Don’t let me down, and She came in through the bathroom window. (By the way, these juicy table scraps will also be served beginning Thanksgiving in a new three-part, six-hour Disney + documentary series. The Beatles: Get Back, produced and directed by Peter Jackson.)
The rock-solid nature of the LS50 Wireless II cabinets, a curved front panel made of Dough Molding Compound (polyester resin, fiberglass and calcium carbonate) and well-reinforced MDF sides, should certainly contribute to the robust coloration. from the speakers. free acting. But I suspect it is what’s more a factor in the less than stellar Wi-Fi connectivity I’ve experienced.
While Speedtest on my iPhone 12 Pro recorded Wi-Fi download speeds in my listening room of 320 Mbs, the informational KEF Connect app tracked its speakers processing only 17 Mbps. During prime time in my neighborhood, that rate reception rate dropped to just 4.9 Mbps.
That’s still fine for catching internet radio and the current free / premium versions of Spotify (160Kbps / 320Kbps respectively). But that speed wasn’t enough for Tidal, and it’s half what it takes to stream Qobuz without stuttering.
The KEF user manual kindly suggests keeping the speakers “within line of sight” of your router if you want to use Wi-Fi. When I tried that remedy, the transmission speed of the speakers jumped to 36 Mbps, but my router is not in the room where I hang out and listen to music.
So, I ended up asking my electrician friend John Siemiarowski about Electrical sorcery) to run an ethernet cable from the router to my listening room. Once connected to my network, the transmission speed of the KEFs skyrocketed to 79Mbps, which made it very happy in the land of high resolution transmission.
Bottom line: Yes, these things can be demanding. But the best is never cheap. And the KEF LS50 Wireless II offers the best it can. Even if you can’t afford a pair now, it’s worth an in-store instructional audition. This is the stuff that home audio dreams are made of.