KEF LS50 Meta loudspeaker Associated Equipment

Sidebar 2: Associated Equipment

Analog source: Linn Sondek LP12 turntable with Lingo power supply, Linn Ekos tonearm, Linn Arkiv B cartridge, Channel D Seta L phono preamplifier.
Digital sources: Roon Nucleus+ file server; Ayre Acoustics C-5xeMP universal player; PS Audio PerfectWave DirectStream, MBL N31, and Okto Research dac8 Stereo D/A processors, Ayre Acoustics QA-9 A/D converter.
Preamplifier: MBL Noble Line N11.
Power amplifiers: Parasound Halo JC 1+ monoblocks.
Integrated amplifier: NAD M10.
Loudspeakers: Bowers & Wilkins 705 Signature, KEF LS50, Marten Oscar Duo.
Cables: Digital: AudioQuest Vodka (Ethernet), AudioQuest Coffee (USB), DH Labs (1m, AES/EBU), Esperanto (S/ PDIF). Interconnect: AudioQuest Wild Blue (balanced) with Parasounds, AudioQuest Fire (single-ended, with NAD). Speaker: AudioQuest K2. AC: AudioQuest Dragon Source & High Current, manufacturers' own.
Accessories: Celestion 24" loudspeaker stands; Target TT-5 equipment racks; Ayre Acoustics Myrtle Blocks; ASC Tube Traps, RPG Abffusor panels; AudioQuest Niagara 5000 Low-Z Power/Noise-Dissipation System (amplifiers) and AudioQuest Niagara 1000 Low-Z Power/Noise-Dissipation System (source components). AC power comes from two dedicated 20A circuits, each just 6' from breaker box.
Room: 20' (left side), 25' (right side) × 16' × 8'.—John Atkinson

COMPANY INFO
KEF, GP Acoustics (UK) Ltd.
US distributor: GP Acoustics (US) Inc.
10 Timber Lane
Marlboro, NJ 07746
(732) 683-2356
ARTICLE CONTENTS

COMMENTS
latinaudio's picture

It´s written on my Santa´s letter this year...

Anton's picture

https://images-na.ssl-images-amazon.com/images/I/71P6kaBRLnL._AC_UX385_.jpg

Charles E Flynn's picture

The "Introducing the Meta" section of the review gives the price as "a penny less than $1500/pair", as does the KEF.com website, but the Specifications section has " $1599/pair".

tonykaz's picture

If you can wait for a few months, these Meta versions ( previously loved ? ) will probably sell for about half of MSRP.

The earlier versions are selling for $700 approximately which is a good thing for a Chinese product.

Schiit gear sells on eBay for closer to 75% of MSRP but it's all made in USA.

A used pair of British made LS3/5a will sell for Considerably More than these KEFs but they are all the exact same loudspeaker as the BBC design mandates. ( the venerable LS3/5a remains a Gold Standard Transducer )

Tony in Venice

John Atkinson's picture
Charles E Flynn wrote:
The "Introducing the Meta" section of the review gives the price as "a penny less than $1500/pair", as does the KEF.com website, but the Specifications section has " $1599/pair".

A slip of my typing finger. Have corrected the error and my thanks for finding it.

John Atkinson
Technical Editor, Stereophile

Charles E Flynn's picture

You are welcome, and thanks for another fine review and excellent photography.

Dan5000's picture

Thanks John - Because of your rec, among other reasons, I just ordered an M10 as a first (easy) step into this world. Do you think these pair well overall? A significant upgrade in sound (for the price) against something like the B&W 606 Anniversary?

Thanks.

John Atkinson's picture
Dan5000 wrote:
Thanks John

You're welcome.

Dan5000 wrote:
Because of your rec, among other reasons, I just ordered an M10 as a first (easy) step into this world. Do you think these pair well overall?

Yes, especially as the M10 incorporates Dirac Live EQ, which can compensate for room acoustic problems and extend the KEF's low frequencies. See how Dirac works with the original LS50 at www.stereophile.com/content/nad-masters-series-m10-streaming-integrated-amplifier-trying-dirac-live-room-correction.

John Atkinson
Technical Editor, Stereophile

Mikk's picture

Good work Kef- a high-performance speaker at a great price. As suitable for audiophiles as for non-audiophiles, and would look great in any room.
The only question now is how they compare with the wireless version, and what sort of gear would be needed to get the passive version to sound on-par with the wireless version!
A pair of either, with well setup subs, should be very impressive.

aweingarten's picture

For those of us not allowed to put speakers 3 feet from the rear-wall, was wondering how far from the rear-wall you would recommend for these?

tabs's picture

One thing to remember is that the LS50 Metas come with two options for stuffing the ports and a guide in the owners manual in how to approach it. If I remember from my setup a few days ago, if the rear panel of the Meta is between 0 and 20cm from the wall, they recommend fully stuffing the port (donut hole foam in donut ring). From 20-50cm they recommend using the hollow donut ring foam piece to partially close it. From 50cm on you run the ports wide open.

Mine sit 25cm from my rear wall in a relatively small room. With the ports open at that position, bass was indeed too prominent. With the hollow donut ring in place that helped perfectly. I’ve since done a bunch of REW measurements and the donut ring brought them perfectly into line with the rest of the frequency response.

JRT's picture

Dutch & Dutch 8C active loudspeaker is much more expensive, but it was designed to work well in close proximity to the room boundary behind the loudspeaker, so it may be a solution to your problem which offers very much better performance.

Alternatively, move the loudspeakers and listening chair into the proper listening position when listening to the loudspeakers, and move them back to where you are "allowed" to keep them when not using them.

Fruff1976's picture

"(I am reminded of something Bob Stuart had told me in the 1980s, that loudspeakers that have the same width as the human head always excel with vocal reproduction due to the similarity between the sounds' intensities."

So this is why all of those gigantic speakers at the audio shows sound ridiculous....I listened to the flagship Borrensen speakers at Axpona that people were raving about and Joe Satriani sounded like a hot air balloon head. Not exactly my cup of tea.

Sam Tellig's picture

Sam has moved on to the LS50 Meta from the original LS50 Anniversary. Resolution is stunning, the best I've heard since I sold my Quad ESL 2805 electrostatics. I hear no cabinet colorations. There is nothing to smear the sound. What this means is you can save money on speakers and buy the best possible electronics. I am using the Chord Qutest DAC, BTW. Cheapskates have never had it so good!

latinaudio's picture

I miss your column and the way you wrote stories about the products and their origins. Greetings to Marina and Merry Christmas.

sdecker's picture

John, what's your guess as to why KEF would rewire the tweeter 'out of phase' versus the previous version? I could find no reference to that or other related crossover changes in their Meta White Paper. If no related changes are made to a major redesign of a classic, wouldn't this be audible, and/or suspicious? (I listen to Thiels, so perhaps this is more important to me than to KEF? Though I just bought a pair of these!)

Jim Austin's picture

It's a good question.

Just a guess, but the answer may be found in Fig.9. Compare the frequency response near the 2.1kHz crossover frequency with the original: A very shallow depression--almost flat--replaces a small but significant rise.

Also note the slight change in the crossover frequency relative to the original: 2.1 vs 2.2 kHz. Hardly surprising. They've apparently found a better way to do the crossover--simple as that.

Jim Austin, Editor
Stereophile

daltonknox's picture

Preferring an MQA recording is not toeing the Stereophile party line - risking banishment to the gulag?

JRT's picture

...and that proprietary MQA audio, directly to the KEF LS50 Wireless II network attached active loudspeakers.

For somebody like your niece or daughter who just wants to listen to some good music, isn't concerned about the proprietary nature of MQA if it works well enough, and isn't interested in fussing with a lot of gear and physical media, that may be a very good solution.

Neil Jetty's picture

Hi John

Is the Meta strong enough vs. the orignal LS50 to make you consider trading up?

John Atkinson's picture
Neil Jetty wrote:
Is the Meta strong enough vs. the original LS50 to make you consider trading up?

I'm seriously considering doing so once my wallet allows it.

John Atkinson
Technical Editor, Stereophile

Charles E Flynn's picture

Just announced: https://us.kef.com/kc62-subwoofer.html

agb's picture

Until recently the Brit audiophile product was off my radar.

On a whim for my Budapest flat I purchased the second pair of LS50's, this time the wireless W-designated model. Simply put, it way exceeded my expectations here in the US where I tested them first. The powered model was significantly better than the base speaker with any amplifier I used it with. I am speaking of expensive amps.

The built-in DAC/amps outperformed the nekkid speaker with a far more expensive external amplifier. On many levels. There is no upside to external components and wires not as well matched to the driver as KEF accomplished within the whole package. I think others have had the same experience as I.

But the KEFs didn't realize their performance limits until I dragged them to Budapest in two luggages. My flat there, in an 1847 World Heritage building, has 4 meter high ceilings, meter thick walls, and parquet. Solid that is.

I applied some EQ to take down the bass (along with the speaker's own built-in DSP functions to limit the output, which was overwhelming). I used real time FFT with peak hold on a variety of music streams - with optical wire, no USB here - to get a response almost the same I was getting with two high end headphones. I could superimpose one graph on the other.

It's obvious: KEF got things right with an unusual, but obviously brilliantly-designed and well-built driver in a well-braced cabinet. Pretty much the same driver KEF uses in its $32,000 BLADE. And that tells us a lot.

With the DSP the W model is great; the Meta version probably addresses the issues I had to deal with, with the EQ necessary on the earlier model. John addressed these improvements, and accordingly, I may even buy the newer model for one of my rooms in the US. I am that pleased by the sound of this Brit.

Kick ass - these KEFs are really an unbelievable value at the price.
John probably understated his case for them.

To sum up: At the price, the quality of build and sound, at least speaking for the powered version, KEF made these as "keepers."

Charles E Flynn's picture

From https://us.kef.com/speaker/flagship-hi-fi-speakers/ls50/ls50-meta.html :

LS50 Meta

Driver Unit: 12th Generation Uni-Q with MAT+ 40% frequency response smoothness

Driver rearward Source Absorption: 99% driver rearward sound absorption by MAT

Mid-band Total Harmonic Distortion (THD) at 90dB/1m: THD 0.07%
Extremely low distortion by driver motor redesign

LS50

Driver Unit: 11th Generation Uni-Q

Driver rearward Source Absorption: 60% driver rearward sound absorption by vented tweeter

Mid-band Total Harmonic Distortion (THD) at 90dB/1m: THD 0.1% Mid-band at 90dB/1m

Butter's picture

Maybe I don't know how to read all the measurements, but is there a way to understand how well the LS50 meta would play loud in a larger room. I understand it's a compact insensitive speaker.

I have LS50 Anniv editions in my office (15x15) and don't "blast it" because I'm in the house. But my new office (30x35) will be in another building, so I'm thinking of getting LS50 Metas a sub, and say... a NAD M33. I wouldn't mind getting floorstanders if there was a way to quantify the high SPL capability between different options. The price point for the LS50 is just so attractive and I love my Anniv editions, I'm seeing if I should hit the shops to demo some floorstanders.
Thanks for any advice.

JRT's picture

It would be interesting, informative and useful to see a curve showing EPDR magnitude with respect to frequency as a third curve added to the graphic showing electrical impedance and phase.

This is just a suggestion, and is not a negative criticism of the measurements and associated commentary which you are already providing, all of it worthwhile. Thank you for your efforts.

dc_bruce's picture

Mr. Atkinson: somewhere I recall you praising Karen Carpenter's work in a prior review; and you've done it again here. Just so! Being your contemporary, I recall when the Carpenters were making hits. I pretty much dismissed them at the time for political reasons. (I think President Nixon was a fan.) Courtesy of my wife, I own an LP of their "Singles" which I play often. While I don't care for some of Richard Carpenter's arrangements, his sister shows an unbelievable vocal range and maturity for someone her age. And to think that she supposedly thought of herself as a drummer, not a singer! In my opinion, her vocal command far exceeds any of her contemporaries, especially the over-praised Linda Rondstadt. Linda had a strong voice but unstable pitch, as her foray into the standards with the assistance of Nelson Riddle shows all too well. The original LS-50s are wonderful with Karen Carpenter's voice. Like you, I plan to upgrade to the Metas when the piggy bank is full.

Jchefs7@msn.com's picture

Hmmm nice writing but for a scientific review go to audio science review

KEFLS50W's picture

Apparently the real reason the Metas sound different to the LS50s is that they deploy Sealed Suspension Technology (SST) initially developed in the 3001 SEs as a prototype. It evens out turbulence. The tech never made it to the LS50s even though they’re newer than the SEs which is why they can sound a bit shouty if pushed hard. The Metamaterial is understandably probably more of a marketing gimmick.

canonken's picture

I just got a pair yesterday and it has been love at first listen.

I'm driving them with a McIntosh MC462 (450 watts per channel, 100+ pound monster), which provides similar power to the amp the reviewer used. I cannot believe how much power these speakers need! Not a flaw or a bad thing, but WOW these things are power hungry, be warned, make sure you either try these on your amp, or plan accordingly. At 'adult loud' levels the needles on the power meter are routinely staying in the 10-50 watt range for the entire track. That is a TON of power. Curious to try these with a less-powerful amp and see what happens.

georgehifi's picture

Looking at the anechoic response, there seems to be quite a dip at 20khz with these compared to the old model, any ideas why?? Zobeled?

https://www.stereophile.com/images/1212KEF50fig3.jpg

Cheers George

John Atkinson's picture
georgehifi wrote:
Looking at the anechoic response, there seems to be quite a dip at 20khz with these compared to the old model, any ideas why??

I suspect it's diffraction-related. You can see from the lateral dispersion plot that it tends to fill in to the speaker's sides.

John Atkinson
Technical Editor, Stereophile

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