In an absolute sense, you could find better speakers, better streamers, better amplifiers, and better DACs, but no product I know of has combined all of these functions and achieved this level of performance for this amount of money. In the LS50W, KEF has created a benchmark, whole-cloth solution by which all other such systems should be measured.
Highlights

KEF LS50W Powered Music System

  • Based on KEF’s award-winning LS50 compact reference monitor
  • Simple to set up
  • Plentiful input and connectivity options
  • Cabinet finishes and placement options offer lots of flexibility
  • Considering the price, the overall performance sets the bar at stratospheric heights
Introduction

KEF LS50W Powered Music System Review

KEF celebrated its 50th anniversary in 2011. As part of that anniversary, KEF released the LS50 in 2012, a compact reference monitor that promptly set the world on fire. Still in production, the LS50 quickly achieved a cult-like following due to its enormous value proposition. For $1500, there was nothing on the market that came close to its world-class transparency and definition. While the overwhelming majority of critics and consumers raved about it, it was not completely without its detractors.

KEF LS50W Powered Music System SPECIFICATIONS
Dimensions (Inches):

11.8 H x 7.9 W x 12.1 D

Weight (pounds):

Left (22); Right (22.5)

Drive Units (Uni-Q array):

One-inch vented HF aluminum dome (HF); 5.25-inch magnesium/aluminum alloy cone (LF)

Amplifier Output Power (watts/per speaker):

30 (HF) + 200 (LF)

Maximum Frequency Range (adjustable) (-6dB):

40Hz – 47kHz

Maximum Frequency Response (adjustable) (±3dB):

45Hz – 28kHz

Max Peak SPL:

106dB

Inputs (up to 24bit resolution, depending on source):

2.4GHz/5GHz dual-band Wi-Fi network (IEEE 802.11a/b/g/n); 10/100 Mbps RJ45 Ethernet; Bluetooth 4.0 with aptX® codec (eight device memory and range up to 10m); USB Type B (up to 192kHz); TOSLINK Optical (up to 96kHz); RCA Line Level Analog Input

Output:

Single Subwoofer

Compatibility:

Spotify Connect, Tidal HiFi, and Roon

MSRP:

$2199

Colors:

Gloss White with Copper, Gloss Black with Blue; Gloss Grey with Red
KEF LS50W Product Page

Company:

KEF

SECRETS Tags:

KEF, LS50, All-in-one speaker, Wireless, Streaming

The LS50 is surprisingly full-range, but it is still a small speaker and will struggle in large rooms. And even when its stature is well-suited to the room, the LS50 demands both quantity and quality of amplification and sources. For example, searching audio-related forums will uncover opinions of those who were initially disappointed with the LS50, often describing its sound as harsh or thin. Dig a little deeper, however, and you will understand the reasons behind those opinions. Most often, it is because the LS50 was paired with components on the level that one would normally expect to pair with a $1500 speaker—that’s the mistake. The LS50 is not a normal $1500 speaker. The LS50 is better understood as a high-end studio monitor, which strives, first and foremost, for transparency. The price of the LS50 makes it particularly susceptible to being mismatched to electronics not quite up to the task. In fact, I too was initially frustrated with the LS50 given it’s demanding nature. Eventually, I found that the least expensive amplifiers that worked well with the LS50 in my room were the $2500 Parasound Halo integrated and the $2600 Rogue Cronus Magnum II. If you go with the Rogue, you’d also have to throw in a decent DAC, so figure $5000. The Parasound would be the more economical choice as it features a quality built-in DAC, but even then, that’s $4000, which is nearly double the price of the LS50W. You’d also need to account for the cost of speaker cable and interconnects. The LS50W is therefore a solution that puts all this potentially anxiety-inducing planning, experimentation, and expense aside.

Design

In the LS50W, KEF retains the UNI-Q driver configuration of the LS50, but that’s where the similarities end. Without adding very much at all to the external form factor of the LS50, KEF includes two discrete amplifiers per speaker, which power each channel of the two-way LS50W with 230 watts in a bi-amp, dual mono configuration. 200 watts of Class D drive each of the 5.25 inch woofers and 30 watts of Class A/B drive each of the one-inch tweeters. As mentioned above, the LS50 is not the easiest speaker to drive and these power ratings reflect that.

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While KEF may have been able to justify the LS50W’s $700 premium by stopping at the amplifiers, they didn’t. The LS50W also includes a built in wireless streamer and upsampling D/A converters. Not only do discrete amplifiers power each of the four drivers, but each driver also has its own DAC, which, significantly, permits granular control of its behavior and response. As the specifications above will tell you, connectivity options are numerous, including Wi-Fi, Bluetooth, asynchronous USB, a digital optical input, and an RCA line-level analog input (converted to digital). An LS50W app (iOS and Android) facilitates network setup, music streaming, playback, and significantly, allows adjustment to both the speakers’ and any connected subwoofer’s frequency range and response. I had not heard much about the DSP features, so it came as a very welcome surprise. KEF even throws in a remote control and includes a very slick OLED touch bar on the top of the master speaker.

KEF LS50W Powered Music System Review Remote

One very thoughtful design choice of note is that the color scheme of the remote control matches the three available color combinations of the speaker. For example, you get a white remote with copper-colored printing with the gloss white speakers.

KEF LS50W Powered Music System Review Remotes

Setup

The “W” in the LS50W is supposed to mean wireless, but that’s an oversimplification. As the specifications indicate, the LS50W does feature Wi-fi and bluetooth, but everything else is going to require cable. Each speaker needs to be fed AC power and the speakers connect to each other via a supplied ethernet cable. All sources connect to the master speaker.

KEF LS50W Powered Music System Review Speakers

KEF LS50W Powered Music System Review Left Speaker

KEF LS50W Powered Music System Review Right Speaker

There are two ways to control the LS50W’s DSP settings. The settings for different placement options are directly accessible on the back of the master speaker (and also available via the app). They include settings for placement on a tabletop or on a stand and close to a wall or in “free space.” The slave speaker contains a knob to adjust the left/right balance. The LS50W app is the second way to adjust the sound settings and there are a multitude of options offering precise control over the speakers.

KEF LS50W Powered Music System Review Program

KEF helpfully provides a number of how-to videos regarding the set up of the LS50W, one of which covers the sound settings in great detail. These settings are very much worth playing around with as they definitely change the sound of the speakers and allow you to tailor the sound to your environment. For example, I found it very beneficial to disable the crossover in my subwoofer and instead use the filtering options via the app. Notably, KEF continues to improve both the firmware and the app, adding to and refining the features of the LS50W. Owners are encouraged to visit the KEF website to ensure they have the most up-to-date firmware version.

I had dedicated stands, which I used throughout the evaluation. The speakers were set approximately eight feet from both each other and the listening position. They were approximately four feet from the side walls and 30 inches from the front wall. I ended up toeing them in only slightly. Because my router was close, I hard-wired them to the network via ethernet. I connected the digital audio out of my TV via the optical cable and my turntable (through a phono pre-amp) via the analog input. It was all very easy. KEF’s manual is simple to follow and the app works very well to finish and tweak the set-up. Also of note, the quality of the packaging is great and it reminded me of how Apple packages its products, all very neat and elegant, which makes things easy to find and gives you the impression this is a premium product.

In Use

The LS50W app allows you to access all the music on your phone (via the Wi-fi connection) as well as the servers connected on your network. I found this was the method I played music the majority of the time. I also connected my laptop via USB on occasion, but while very happy with the sound through Audirvana, this was not convenient as my laptop is my only computer and my USB cable is only 1.5 m. I also watched a great deal of streaming television via Roku, the digital audio for which was routed out of my TV via the optical cable into the LS50W. I also used a turntable, the GEM Dandy Polytable, and the Sutherland 20/20 phono preamp.

Having access to tens of thousands of songs is a great convenience and when that access is fast, simple, and reliable, it really allows you to enjoy your music collection, which should be the goal. As I started to get to know this system, I was initially struck by how different the LS50W sounded from what I recalled about the LS50. As the hours wore on, the LS50W sounded, for lack of a better word, smoother. I expected some edginess here and there, but there was none. I also noted the LS50W can play to incredibly loud volumes. I also had no trouble getting ideal bass response because of what seemed like perfect integration of my subwoofer (JL Audio E112). Watching TV became like sitting through a great home theater surround-sound demonstration. I was blown away.

After getting around to more critical listening, I was happy to discover the LS50W did not lose the transparent midrange I remembered from the LS50.

Peter Gabriel
Peter Gabriel “So”

Listening to flac files of Peter Gabriel’s 1986 classic So, I was struck with just how well “Sledgehammer” has held up. That odd 20-second flute intro and wham! Two things stood out. First, I don’t recall this song having such prominent bass. Second, the lead vocal is way louder in the mix than I remember. Gabriel’s voice seems so confident and clear.

There are some horns in the mix as well and the weird flute makes another appearance later in the track. There is also a female backing vocal. There is a lot going on, but it’s all sorted out and wonderfully expressed through the LS50W. There is more separation and definition than I generally recall hearing from the LS50.

The sound is altogether more expansive, which adds more musicality and enjoyment to the listening experience. The surprising amount of bass and the overall energy is also present in “That Voice Again,” which, while such an 80s song, manages to sound fresh through the LS50W. It’s all very lively, with lots of detail and texture, especially in the drums. What’s most impressive listening to this album is that the LS50W is not at all shy about playing loudly. In fact, this system will play very loudly and with the impression that clarity increases the louder you go. It all seems so effortless.

If you really want to understand how the LS50W’s clarity and precision can drive you into the core emotional and communicative aspect of music, play Bjork’s 2015 album, Vulnicura.

Bjork
Bjork “Vulnicura”

Other than the orchestral/electronica style Bjork is known for, this album sounds very different from her prior work. She’s at the end of a twelve-year relationship and is in absolute anguish. The album’s first track, “Stonemilker” portends what’s to come. You’d expect lyrics like “Show me emotional respect, oh respect, oh respect,” to be delivered with anger, but Bjork doesn’t do predictable. It sounds as if she is conflicted about what the future of what her relationship holds.

For now though, she lets the cello strings and the electronic bass machine tell us how big a moment this is, how important her realization is that trying to get her husband to open up emotionally is like trying to get milk from a stone. The song “Black Lake” is about drowning and for 10 minutes and eight seconds, Bjork drowns in heartbreak. The Museum of Modern Art in New York recently had a multi-media retrospective of Bjork’s work in which this song featured prominently. As she sings “My soul torn apart / My spirit is broken / Into the fabric of all / He is woven,” the strings wail away, perfectly synced to the excruciating lyrics. There are long passages in this song where a single note is held for second after second, spanning 15, sometimes 30 seconds. As I listen, the tone reminds me of the sound an EKG makes when the heart stops—flatline. The LS50W swirls you into the middle of this turbulent sea. The LS50W’s clarity and directness is here unforgettable.

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I don’t have a good sense of how many potential LS50W customers will use a turntable, but happily, the option is there for you to do so. You will need an external phono pre-amp, as that is the one thing not already built into the LS50W. However, if the idea is to maximize convenience and space-savings, a turntable really does not make a ton of sense in this system and when you see how much easier listening to music is from network storage or streaming, a turntable may feel very antiquated. Nonetheless, I thought the sound quality of my analog set-up through the LS50w was quite good, but perhaps due to the digital conversion of the analog signal, it did not sound quite as good as listening to my main set up. I must acknowledge that this is a problematic comparison because my main system is quite a bit more expensive and slightly different in overall character (Naim amplification and Focal speakers). If I had to pin down the difference, what I thought was less good was the presence of the LS50W’s smoothness that I had noticed early on. Don’t get me wrong, it’s not that the LS50W removed the records’ crackles and pops, or made records sound like CDs, but as with the Devialet amplifier I had (which, coincidentally, also converted the analog signal to digital), the inherent liveliness of several records was diluted. I imagine that this subtle shift may not be apparent with a different turntable, or a different cartridge (perhaps a moving magnet), but I cannot say. It is only because the LS50W is so accomplished that these nits got noticed. In no way does the performance of my analog set-up diminish my enthusiasm for or recommendation of the LS50W, but if you do have a lot invested in your analog set up, I think an audition is a must. The LS50W offers so much for so little that it would make a great second system as well.

Conclusions

I foresee lots of products in the future that will try to achieve what the LS50W has accomplished. For now though, it is the king of the hill. Performance and value is quite extraordinary.

Likes
  • Impressive all-around performance
  • Incredible value
  • Build quality is fantastic, color options are great
  • Connectivity options are plentiful
  • App is a pleasure to use
  • LS50W firmware and app continue to be updated and improved
Would Like To See
  • A big brother, perhaps a floor-stander?
  • Built-in phono stage
  • More colors!

It’s impossible to rate the individual contributions of the LS50W’s amplifiers, the streamer, and the DACs. However, having owned the LS50, I can say with confidence that you cannot achieve this level of performance at this cost and you certainly cannot achieve the convenience and space-savings this system offers.

  • Boomzilla

    Wait – I can stream music wirelessly to the LS50W speakers from my source, but the two speakers have to be connected to each other by an Ethernet cable? Then why bother with wireless in the first place? That umbilical Ethernet cable ruins the entire concept of wireless speakers! I don’t see that this is any different from normal passive speakers, except that it costs more and the wires are hung differently.

  • Robert Gaboury

    The two speakers need to be connected together because it’s still impossible to wirelessly synchronize the two channels. I am not aware of any wireless system that can effectively get two channels in perfect sync (no time delay)

  • Boomzilla

    Understood – but what an opportunity for some clever engineering… After all, if synchronization can be established via an Ethernet cable, one would think that a synchronizing clock signal (Bluetooth? WiFi different channel? Even Infrared?) could be used instead. After all, the whole goal of wireless speakers is to be wireless!

  • Robert Gaboury

    The term wireless must have been coined by someone in Marketing 🙂 It is true that this is a great engineering opportunity!

  • Your A Looser Trader FotD™

    Apple’s Airplay2 will do this, UE’s Megaboom speakers can do this, and Sonos soon will (they are adding Airplay2).

  • Boomzilla

    Very good review, by the way – Thanks!

  • mp

    Looks like a nice option for a higher end PC/workstation speaker system. As a general living room sound solution, not so much.

  • Richard Townsend

    It’s very different because the cross over is in the digital domain, the amplifier response is tailored to the drive units, and there is dsp to adjust the frequency response to fit the room.

  • Mars2k

    Except that you don’t just need Ethernet wires you need power cables. The question is therefore is the sound worth it.

  • Matias

    Now KEF just needs to roll this technology out to the R series!

  • Sir Winsalot

    Perhaps they could have named them the KEF 802.11, or KEF Bi-amped, or KEF Streaming or KEF System-in-Two Boxes speakers for those who wish to be pedantic. There is no such thing as a wireless speaker system unless it is battery powered, and even then it is only wireless most of the time. Seems to me the point was that you can stream to the system wirelessly from a smartphone, computer, etc. That said, I don’t think the ability to do that is the selling point for people looking for improved performance compared to the LS50. It’s having amplifiers that are optimized to the drivers and the benefits of filtering in SW instead of conventional crossover networks.