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New KEF LS50 collection with new Metamaterial Absorption Technology (MAT) coming.

Kachda

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How long before this tech is introduced into other KEF lines? Like R3s etc.
The R3 is just a couple of years old, they may take a while. Or who knows, they may introduce it next month :)
 

ElNino

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How long before this tech is introduced into other KEF lines? Like R3s etc.

KEF often does relatively long product cycles. The R series went eight years between refreshes, and the LS50 longer than that. (The LS50W is an exception, but it makes sense that they need to keep it aligned with the LS50.) I doubt they'll refresh the R3 anytime soon. They share basically the same 12th gen Uni-Q driver anyway, with the exception of the metamaterial back chamber.
 

Snoochers

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KEF often does relatively long product cycles. The R series went eight years between refreshes, and the LS50 longer than that. (The LS50W is an exception, but it makes sense that they need to keep it aligned with the LS50.) I doubt they'll refresh the R3 anytime soon. They share basically the same 12th gen Uni-Q driver anyway, with the exception of the metamaterial back chamber.

I guess I thought this is a relatively easy change to make to the speakers and to leave them untouched otherwise instead of waiting 5 years or whatever to change them!
 

napilopez

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I do kind of wish KEF had been more daring with the LS50W II's acoustics. I'm getting spoiled by compact speakers that can reach into the 20s -- Buchardt A500, Devialet Phantom Reactor, Bowers Formation Duo, etc . It would've been cool to see side-firing or rear woofers or something to increase the usable surface area and then turn things up in the amp department to account for the small size.

Yes, distortion is a trade-off, but it's pretty much always worth it IMO, especially for the target audience of these speakers. Even more so ocnsidering the speaker has already has subwoofer outs and bass management built-in should you want cleaner bass in the future.
 

napilopez

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KEF just sent me the whitepaper for the new speakers (it's up on the site now too). There are spins! Even Early Reflections components!

It looks a lot like the LS50 frankly, though refined. On axis is once again a bit uneven, so you'll want to listen off-axis. The low mids in particular seem smoother and the LW looks quite nice.

Note the scaling is too wide for my tastes, but kudos to KEF for providing such extensive measurements.

Here's the LS50 Meta:

1600798646546.png


Early Reflections components:

1600798756051.png


The LS50 Wireless II however, is the real deal. Other than the on-axis being slightly uneven, It is basically Genelec quality:

1600798878049.png


1600798907307.png


Still need to peruse through the rest of the whitepaper, but thought I'd share this first.
 
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Ron Texas

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@napilopez the new ones definitely measure better. It's likely their preference score will go up. I'm not sure the difference will be dramatic as compared to the old ones with EQ and a sub.
 

napilopez

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And here's a graph showingt he effectiveness of the tweeter's metamaterial absorber:

1600799441735.png


EDIT: and when combined with a waveguide for the rear of the tweeter and some porous material, this is the absorption spectrum:

1600799667826.png


Looks very promising!
@napilopez and @hardisj Please request a sample for review! :D

You know I already did ;)
 

aarons915

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KEF just sent me the whitepaper for the new speakers (it's up on the site now too). There are spins! Even Early Reflections components!

It looks a lot like the LS50 frankly, though perhaps refined. On axis is once again a problem, so you'll want to listen off axis. The low mids in particular seem smoother though.

Note the scaling is too wide for my tastes, but kudos to KEF for providing such extensive measurements.

Here's the LS50 Meta:

View attachment 84305

I was hoping the whitepaper would show some kind of measurements, awesome that they actually give a proper CTA-2034 style. Of course the wireless is better because of the filters they can use to smooth the response but the passives seem very good too. I don't see anyone thinking of these as bright like the originals, I expect them to be very smooth. Some PEQ from 200-2k seems to be all that's needed to get these to be even more neutral but as is they should be very smooth and the large peak at 2k is completely gone, very impressive. I look forward to your impressions and measurements.
 

napilopez

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I was hoping the whitepaper would show some kind of measurements, awesome that they actually give a proper CTA-2034 style. Of course the wireless is better because of the filters they can use to smooth the response but the passives seem very good too. I don't see anyone thinking of these as bright like the originals, I expect them to be very smooth. Some PEQ from 200-2k seems to be all that's needed to get these to be even more neutral but as is they should be very smooth and the large peak at 2k is completely gone, very impressive. I look forward to your impressions and measurements.

Yes, I especially noted the improvement in the wireless because the original still had a bit of a directivity mismatch between 1-2k despite being good overall:

1600800784509.png


(not sure why this measurement was so tilted, but the mismatch is evident regardless)
 

TimVG

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KEF just sent me the whitepaper for the new speakers (it's up on the site now too). There are spins! Even Early Reflections components!

It looks a lot like the LS50 frankly, though refined. On axis is once again a bit uneven, so you'll want to listen off-axis. The low mids in particular seem smoother and the LW looks quite nice.

Note the scaling is too wide for my tastes, but kudos to KEF for providing such extensive measurements.

Here's the LS50 Meta:

View attachment 84305

Early Reflections components:

View attachment 84306

The LS50 Wireless II however, is the real deal. Other than the on-axis being slightly uneven, It is basically Genelec quality:

View attachment 84307

View attachment 84308

Still need to peruse through the rest of the whitepaper, but thought I'd share this first.


Looks exactly like the target I use for correcting loudspeakers. Flat listening window, and tilt down to avoid peaks/rising response in the on-axis.. @Maiky76
 

napilopez

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Here are those measurements with proper scaling, using the scientifically-determined best spinorama color-scheme:

LS50 Meta:

LS50 Meta Spin.png


LS50 Wireless 2:

LS50 Wireless II Spin.png


For reference, here's how the listening window and ER, the two most important curves, imo, compare to Amir's spin for the Genelec 8341:

LS50W II vs Genelec 8341A.png


So very much comparable. Eagle-eyed observes will note the Genelec appears to have ever so slightly better directivity while the LS50W II has an ever so slightly smoother listening window. Probably at the point of being negligible considering the different measurement sources. Though I'm curious how the small woofer will handle higher SPLs, it seems the LS50W will sound excellent in its comfortable range.

EDIT: Also note that the LS50 Meta and Wireless II have absolutely identical DI curves, so getting the passive version to sound like the active one should be a matter of basic EQ. Basically just needs a 1-2dB lift between 2k and 4k and a slight pulling down around the mids.

Here's how the two on-axis graphs compare and the difference between them(offset by 60 dB for display purposes):

Meta vs W II.png


So the difference is quite subtle overall, though of course the LS50W II has some built in extra EQ via the app.
 
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Soniclife

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EDIT: Also note that the LS50 Meta and Wireless II have absolutely identical DI curves, so getting the passive version to sound like the active one should be a matter of basic EQ. Basically just needs a 1-2dB lift between 2k and 4k and a slight pulling down around the mids.
I do wonder if they have considered producing their own convolution file to correct the passive version, Hedd do this, Audeze do it, it seems like a simple bonus feature for buyers.
 

sweetchaos

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Maiky76

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Here are those measurements with proper scaling, using the scientifically-determined best spinorama color-scheme:

LS50 Meta:

View attachment 84343

LS50 Wireless 2:

View attachment 84344

For reference, here's how the listening window and ER, the two most important curves, imo, compare to Amir's spin for the Genelec 8341:

View attachment 84348

So very much comparable. Eagle-eyed observes will note the Genelec appears to have ever so slightly better directivity while the LS50W II has an ever so slightly smoother listening window. Probably at the point of being negligible considering the different measurement sources. Though I'm curious how the small woofer will handle higher SPLs, it seems the LS50W will sound excellent in its comfortable range.

EDIT: Also note that the LS50 Meta and Wireless II have absolutely identical DI curves, so getting the passive version to sound like the active one should be a matter of basic EQ. Basically just needs a 1-2dB lift between 2k and 4k and a slight pulling down around the mids.

Here's how the two on-axis graphs compare and the difference between them(offset by 60 dB for display purposes):

View attachment 84353

So the difference is quite subtle overall, though of course the LS50W II has some built in extra EQ via the app.

Hi,

Would you share your data? I'd like to compare the new version with the EQ for the Original here:
https://www.audiosciencereview.com/...helf-speaker-review.11144/page-22#post-521244

The New version looks very close to the EQ version with better Xover.
 

Maiky76

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Never mind, I scanned the data.

I have spliced the LF of the ON to the other curves and simulated the directivity, so it's probably not perfect but a reasonable approximation.
The scores are only indicative as the resolution of the scans, although interpolated to a correct 1/20th octave resolution, is most probably too coarse.
I have done the same thing for the Kali LP8 and Presonus Eris 8XT. I'll show that at one point.

Kef LS50WII no EQ Spinorama.png

I ran my optimizer for an EQ, this just for fun... this speaker really likes a slope ( -0.215*log(f) after optimization on the LW)
Kef LS50WII EQ design.png

Kef LS50WII EQed Spinorama.png



The regressions: there is a deliberate slope /shelf down to the response.
Kef LS50WII Regression - Tonal.png

I guess the trough centered around 2kHz is also deliberate, BBC dip?
Kef LS50WII Zoom PIR-LW-ON.png


I then made some comparisons with the LS50 data collected by @amirm
first no EQ, there is a definite family resemblance although the new version is a major step in the correct direction.
I am eager to read the subjective reviews/comparisons, are people going to miss the "character" of the original?

Kef LS50 No EQ vs Kef LS50WII No EQ Spinorama.png

Kef LS50 No EQ vs Kef LS50WII No EQ Radar.png


Did the same thing with the LS50 EQed vs the LS50WII no EQ
Kef LS50 EQed vs Kef LS50WII No EQ Spinorama.png

Finally modified the LS50 EQ to roughly match the LS50WII and really see the improvement:
mods to the EQ:
- remove LF boost
- add Highshelf 200Hz, -3dB, Q 0.5 -> deliberate voicing?
- add Peaking 2000Hz, -1.5dB, Q 1.5 -> deliberate voicing?
if one removes what I believe are voicing choices, the EQ version of the LS50 tracks pretty well, we may be onto something ;-)
The biggest improvement seems to be coming from the tweeter section (much smoother thanks to the meta material?) and Xover with a much smoother SPDI

Kef LS50 modded EQed vs Kef LS50WII No EQ.png

Kef LS50 modded EQed vs Kef LS50WII No EQ Radar.png


The new speaker looks like a significant improvement across the board.
 

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TomJ

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The new speaker looks like a significant improvement across the board.

Thank you for a very nice analysis. Yes agreed, across the board. Surprised by all the emphasis on the MAT pad. This is a top-down redesign - new DSP algorithms (surely running on a much more capable FPGA), larger woofer (5.25"), better tweeter / woofer isolation, powerful new amps... Impressive, congrats to the KEF engineering team!
 
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