KEF LS50 Loudspeaker Review 2019
- By wirelessspeakers
- On 14/01/2019
What is the KEF LS50 Wireless?
The LS50 Wireless is an active stereo speaker system, offering all the plug-and-play convenience of a Bluetooth speaker alongside the high-end audio capabilities of proper hi-fi separates.
It’s based on the KEF’s popular LS50 passive speakers, but builds an amplifier, streaming pre-amp, top-quality DAC and a whole suite of digital and analogue inputs into a design that’s only a few centimetres bigger than its muse.
The Wireless moniker refers to the speakers’ capabilities rather than their physical attributes. There are still three main wires to deal with: a power cable for each speaker and a cable that connects the two together.
Still, that’s far fewer than what a system of separates would require to do the same job. In fact, for all this compact setup offers, you’ll really start to question the need for anything more.
The KEF LS50 Wireless are a gorgeous pair of bookshelf-sized speakers that will look great on your desk or in your home theater.
Our unit came in a glossy piano black but there’s a white and silver version as well. The front of the speaker is dominated by KEF’s Uni-Q drivers which puts the tweeter in the center of the bass and midrange woofer. This, claims KEF, allows the speakers to offer a three-dimensional soundstage no matter where you’re sitting and it really works (more on this in the Performance section).
On top of the right speaker you’ll find touch controls for power, Bluetooth, source, and volume. The controls are illuminated when the speakers are turned on and are easy to press, though they don’t provide any tactile feeling since they’re touch control. However, there’s an included remote that offers physical buttons if you miss the tactile feel.
Speaking of the remote, the one that comes in the box is fairly basic that’s just one step above the awful card-sized remotes with membrane buttons that ships with just about every soundbar and preamp. The remote is made of plastic but still feels nice in the hand and it replicates the touch controls on the top of the speaker plus buttons for previous/skip track and mute.
One nitpick we had about the LS50 Wireless is the fact that if you change inputs using the remote control that you have no idea what input you’ve switched to unless you at the panel on top of the speaker. This means you either have to memorize the sequence of inputs or have to get up and look at the speaker. We wish the included speaker included dedicated source buttons to switch instantly instead of cycling through them - but it didn't prevent us from loving the speakers.
The KEF LS50 Wireless packs a ton of features but let’s go over what features make it sound so good. For amplification, KEF designed the LS50 Wireless with two 230-watt power supplies in a bi-amp dual mono configuration. This means each channel gets its own dedicated amplifier for interference-free power delivery.
On board is a DAC for each channel that’s capable of up to 192 kHz and 24-bit sources. While not the bleeding edge in terms of ultra high resolution audio, it’s a solid DAC setup that should last for years to come. We spoke with KEF about why they didn’t include support for new formats like DSD or MQA and were told that the company wanted to design the KEF LS50 Wireless to last as long as possible and decided not to include unproven formats.
In terms of wireless connectivity, the KEF LS50 Wireless supports 2.4GHz/5GHz dual-band wireless N for streaming music over your home server. We tried this with our home Plex server and it worked well streaming high-resolution FLAC files over our network that’s powered by the Netgear X6S Nighthawk router. The mobile app used to browse music and control playback is a bit laggy at times so hopefully KEF and keep improving the mobile app experience.
It’s a bit disappointing that neither Google Cast nor Apple AirPlay are supported, as it would have been easy to control by voice using a Google Home speaker. However, Spotify and Tidal users can control the LS50 Wireless directly, which is a nice touch.
If you don’t have your own music server, Roon, Tidal, or Spotify, there’s always the Bluetooth 4.0 input, which supports the aptX codec for CD-quality sound. Bluetooth sounds good and is convenient to find and stream music from our phone. It’s a little disappointing that aptX HD isn’t supported, as it would have been the Bluetooth input sound even better. But nitpicky audiophiles are not likely using the Bluetooth input for serious listening in the first place.
The inputs keep on coming with optical TOSLINK support for hooking up to sources like your TV. This means you can have the LS50 Wireless be your speaker setup for everything from television, wireless, and analog sources like a turntable. One thing to note that the optical input caps out at 96 kHz 24-bit so the USB input is preferable for connecting a DAC.
Last but not least, the analog audio jacks let you connect your own source devices. This can be a turntable or you can attach your own DAC, if you please.
Around the back of the speakers you’ll find the speaker’s DSP controls. You can specify if you have the LS50 Wireless on a desk or on stands and if they’re right up against the wall or have free space behind to breathe a little. This can also be tweaked within mobile app so you don’t have to go digging behind the speaker every time you want to change a setting. The app has even more advanced controls, which allows you to tweak things like the phase correction and subwoofer crossover.
None of the above would matter if the KEF LS50 Wireless doesn’t sound good. That said, we’re happy to report that the LS50 Wireless sound phenomenal.
Overall, they are staggeringly detailed and their stand-out sonic feature is their holographic imaging and instrumental layering: We could hear exactly where each instrument was coming from and each instrument sounded distinct and never blurry. Soundstage was expansive with good space to the side and above the listener. Resolution is excellent as the speaker can dig for the micro-details that get lost in lesser audio systems.
Tonal balance is extremely neutral, which can be tweaked slightly in the mobile app. You can warm up the sound by setting the speakers to “extra bass” but the balance is near perfect from default to our ears. However, bass-lovers will want to add the optional subwoofer to get visceral bass impact that’s great for movies of electronic music. Without the sub, the LS50 Wireless still produce a surprising amount of bass and we were quite happy without the subwoofer for critical listening.
The LS50 Wireless sounds so good, you’ll be staying up all night rediscovering your music collection because that’s exactly what we did. We played record after record on our Marantz TT-15S turntable to test how various music genres sounded on the speakers. The LS50 Wireless sounded amazing with every genre we threw at it and every input sounded spectacular. In terms of sonic quality there’s very little to nitpick about the KEF LS50 Wireless.
While we’ve reviewed powered and actives options from the likes of Dynaudio, Dali, Linn and Meridian before, none of them has combined such a wide range of features in such an elegant two-box format.
Those that offer a range of inputs usually add an extra connection hub that transmits the signal wirelessly to the speakers. That’s not the case here. There are just the two fully active speaker boxes, arranged in a master and slave configuration. All sources connect to the right (master) speaker, which is then linked to the left by means of a supplied ethernet cable.
As is usually the case, 'wireless' doesn’t actually mean wireless. While these KEFs are better than most, you still have two mains leads – one for each speaker – and the connecting lead between them. Still, they remain a neater solution for getting high-quality sound into the home than traditional separates.
It will come as no surprise to any regular reader that the Award-winning passive LS50s are the basis for this design. The drive units remain unchanged.
These speakers use a Uni-Q array, where the 25mm aluminium dome tweeter sits in the centre of a 13cm magnesium/aluminium mid/bass cone.
This arrangement helps to produce an even dispersion of sound and improves integration between the two drivers. What looks like a grille in front of the tweeter is, in fact, a waveguide that improves its performance.
That beautifully built and finished enclosure is the same as the passive version too, bar a couple of centimetres of additional depth to accommodate the electronics and heatsinking. There are three cabinet options: the Titanium of our review samples, gloss black and gloss white. Each option comes with a contrasting colour on the Uni-Q driver array.
That curved front panel still looks unusual and is made of DMC (Dough Moulding Compound: a polyester resin combined with glass fibre and calcium carbonate). DMC was chosen for its inertness and ability to be shaped.
The rest of the enclosure is made from MDF. It’s heavily braced and strongly damped to minimise any resonances. We don’t tend to talk much about ports, but the one here is unusual in that it’s flexible in a bid to reduce distortion.
The drive unit complement is the latest evolution of KEF’s trademark Uni-Q array. The Uni-Q may look like a single unit, but it’s really a 25mm aluminium dome tweeter in the centre of a 13cm magnesium/aluminium–coned mid/bass. The idea is to improve the way the speaker disperses sound and help integration.
What looks like a grille in front of the tweeter is in fact a waveguide that improves its high-frequency performance. Even without that opinion-dividing colour – KEF calls it Rose Gold – this is one distinctive driver complement.
The engineers have worked hard on the cabinet. That curved front panel is made of DMC (Dough Moulding Compound: a polyester resin combined with glass fibre and calcium carbonate). DMC was chosen for its mass and inertness.
The rest of the enclosure is made from MDF. It’s heavily braced and strongly damped to minimise any resonances.
We don’t tend to go on too much about reflex ports. The elliptical one used to tune the bass on the LS50 is unusual, though. Put your fingers inside and you’ll feel that it’s flexible. This helps to reduce any unwanted midrange distortions.
Given a little space to breathe and mounted on a pair of solid stands these monitors sound terrific. The first thing that strikes us is the quality of the bass performance. For boxes that stand just 30cm high, these speakers deliver deep, agile and powerful lows from the likes of Massive Attack’s Flat of the Blade. But, unlike most small speakers that deliver big bass, the LS50s don’t over-egg things – everything sounds balanced. Move up the frequency range and these KEFs continue to impress. Kate Bush’s vocals on 50 Words For Snow are as clear and articulate as you could wish for. These speakers communicate the energy and drive in a piece of music brilliantly. We’re impressed by the speaker’s seamless integration too, as we are by the way it sets up a huge stereo image populated by securely focused sounds. And, perhaps most importantly, these speakers are fun to listen to. It’s not something (we think) KEF has always managed with its products. Here it has.
Setup KEF LS50
Much of the beauty of the KEF LS50 Wireless lies in the system’s simplicity. Once you’ve connected both speakers to your mains, and then to each other, it’s a case of downloading the KEF LS50 Wireless app (iOS/Android) and following the instructions to get it all onto your network (or hardwiring via Ethernet, if you prefer).
Once discoverable in the app, you can then tap into the speakers to tailor their sound to your room and tastes – but even this is kept accessible to ensure it’s nice and easy to use.
That’s because there are both basic and expert options of the controls that offer largely the same changes, but are just worded differently for different audiences.
For example, in the basic section of the menu, the app will ask you the size of your room and what it’s like (damped, moderate or lively), which translates in the expert menu into bass extension and treble trim. Tweak on either side of the menu and it will change the details in the other.
There are also options for whether your speakers are on a desk or stand (KEF’s Performance stands are a superb pairing, if you have space in your budget) and their distance from a wall, which will tweak the DSP even further.
There are a few extra things to play around with in the expert side, however, including a phase-correction switch and extra controls for connecting an external subwoofer.
The phase-correction switch enables the LS50 Wireless to further compensate for the inherent time delay caused within any crossover. It works with the Uni-Q driver, which helps to keep this in check elsewhere, theoretically offering perfect time-alignment across the audio range.
Experimenting with it is good fun. Switch it on and you’ll hear a subtle-but-noticeable widening of the soundstage, plus a feeling that the sound has been ‘tightened up’ across the board.
You’ll hear more snap in the mids and a touch more bite in the treble, plus a more authoritative, confident overall sound. To an audiophile, it will make all the difference to the experience, but even a less critical ear will hear the benefit from switching it on.
Once you have your speaker settings just so, and have connected your physical sources, you can also use the app to log in to Tidal, or click through to control Spotify directly using Spotify Connect. You can search for connected drives on your network or play back music stored locally on your device too.
While these streamed sources can all be browsed and controlled via the app, physical sources will require you to use the remote or touch controls to switch between them. Again, this feels like something of an oversight, and is something that I hope can be resolved in a future app update for a more harmonious experience.
The app could do with a little bit of work when it comes to performance too. While well laid out and simple to use, it isn’t always the most responsive, particularly the sliding volume control, which I found could be rather temperamental.
Why buy the KEF LS50 Wireless?
If you have a £2000 budget for a proper hi-fi setup, you can be confident you won’t get better when it comes to package or performance than the KEF LS50 Wireless.
When it comes to inputs, the flexibility on offer is second-to-none. Plus the harmonious sound of its components all working together produce a performance so good that it has to be heard to be appreciated.
The system is also convenient, and both simple to use and set up, being accessible enough for hi-fi newbies to get to grips with, without alienating the more experienced listeners in the process.
Are there improvements that could be made? Very small ones, perhaps, which are mostly to do with app functionality. But not only are these niggles fixable, they’re also likely to fade into insignificance when you start listening.
It’s fair to say that spending £2000 on a hi-fi system is a pretty sizeable investment, but this is one that will confidently stand the test of time. If you’re looking for something similar in form and convenience but for far less money and not the same class of performance, maybe look at something like the Wharfedale Diamond A1 or the tiny Ruark Audio MR1 Mk2.
Considering the list of superlatives you can easily apply to the LS50 Wireless, though, to say that it comes highly recommended almost seems to be playing it cool.