Kef Uni-Q generations and speakers

[thewas]

Interesting so why did Amir like the LS50 meta and not the original?

Because they have significant measurement and audible differences as shown in several threads, for example this one and this one. (I own both since they were released, original now almost 10 years and Meta for more than year)
Pablolie is the only one I know who claims their differences are small.
But as it can be seen in white paper of the new versions, the metamaterial tweeter rear radiation absorber is probably one of the smallest measured and audible differences, the main differences come from the different crossover tuning and other changes to the drivers.

 

[pablolie]

Because they have significant measurement and audible differences as shown in several threads, for example this one and this one. (I own both since they were released, original now almost 10 years and Meta for more than year)
Pablolie is the only one I know who claims their differences are small.
But as it can be seen in white paper of the new versions, the metamaterial tweeter rear radiation absorber is probably one of the smallest measured and audible differences, the main differences come from different tuning and other changes to the drivers.

Spoken like a subjectivist

 

[thewas]

Spoken like a subjectivist

Nope, you do that, we have showed you significant objective data differences, while you just make claims without even owning both like I do.

 

[pablolie]

Because they have significant measurement and audible differences as shown in several threads, for example this one and this one. (I own both since they were released, original now almost 10 years and Meta for more than year)
Pablolie is the only one I know who claims their differences are small.
But as it can be seen in white paper of the new versions, the metamaterial tweeter rear radiation absorber is probably one of the smallest measured and audible differences, the main differences come from the different crossover tuning and other changes to the drivers.

I posted the measurements Amir posted on this website. White Papers are.marketing documents (I write them for my company) and NOT scientific papers.

 

[thewas]

I posted the measurements Amir posted on this website. White Papers are.marketing documents (I write them for my company) and NOT scientific papers.

Please really read stuff you quote before making wrong claims, the first link I quoted above shows the differences of both ASR measurements and the second link I quoted above the differences of both Soundstage's and my measurements, not the white papers.

 

[Crosstalk]

Because they have significant measurement and audible differences as shown in several threads, for example this one and this one. (I own both since they were released, original now almost 10 years and Meta for more than year)
Pablolie is the only one I know who claims their differences are small.
But as it can be seen in white paper of the new versions, the metamaterial tweeter rear radiation absorber is probably one of the smallest measured and audible differences, the main differences come from the different crossover tuning and other changes to the drivers.

I too listened to them in a store and since the LS50 was discounted I was thiking it to be a bargain, Upon comparison I really liked the meta over the normal version as the normal felt like it had way too rolled off "air" . If you look at the graph its very easy to understand that. The upper mids are boosted and top end is rolled off. Apparently the upper mid boost exagerrates the last octave roll off and makes vocals more prominent and cymbals well less like cymbals. meta is definitely a more true to source speaker any day. imo if anyone do not hear a diff between them, then well I think that person would be a person who has a large amount of tolerance

 

[tecnogadget]

Has anyone opened an original LS50 and a Meta LS50 and compared crossover parts and values?
I suspect most of the measurements differences are due to new Uni-Q driver and crossover settings than the meta absorption disc…

 

[BoredErica]

Again: If you can't hear a difference that's perfectly fine. Nothing wrong with that. That experience is valid. But to extrapolate from that experience and say *nobody* can hear a difference is way out of line given the measurements.

 

[KMO]

Has anyone opened an original LS50 and a Meta LS50 and compared crossover parts and values?
I suspect most of the measurements differences are due to new Uni-Q driver and crossover settings than the meta absorption disc…

Don't know about values, but the crossovers are significantly different.

KEF waffle a bit about the new crossover in the white paper. The crossover obviously had to be changed because the drivers changed.

A lot of people don't seem to register how much the drivers have changed - there are very significant reworks in there which the marketing has failed to invent a catchy "feature" name for. But they do look exactly the same from the front

The topology of the crossover of the LS50 Meta is shown in figure 24. The smoother response of the new tweeter has resulted in fewer components in the HF filter and the remaining series capacitor (C1) is of higher quality.

The LF filter is similar to that in the original LS50, but includes an extra low-Q parallel resonance branch (C3- R3-L4) to compensate for the higher sensitivity in the driver’s upper midrange due to its lower inductance.

The inductor L4 is the only one in the crossover to have a core. It is vital that only the resistor R3 controls the Q of the branch. To that end, the resistance of L4 (which is subject to change as it heats up when passing current) is kept as low as possible. As the core is a possible source of harmonic distortion if it nears saturation, measurements were taken to relate the current passing through L4 with that passing through L2. Figure 25 shows that it will be seen that the current passing through L4 is much lower and the chances of its core saturating are virtually nil, a fact borne out by the THD measurements of figure 2

To minimise any coupling between inductors, the three in the LF filter are arranged orthogonally and the HF filter is on a separate board, placed well away from the LF filter.

Original can be seen in this DIY audio forum thread. It had three more components in the HF filter, and three fewer in the LF.

 

[Crosstalk]

Don't know about values, but the crossovers are significantly different.

KEF waffle a bit about the new crossover in the white paper. The crossover obviously had to be changed because the drivers changed.

A lot of people don't seem to register how much the drivers have changed - there are very significant reworks in there which the marketing has failed to invent a catchy "feature" name for. But they do look exactly the same from the front


View attachment 186029
Original can be seen in this DIY audio forum thread. It had three more components in the HF filter, and three fewer in the LF.

That being said, we do not know if it’s the crossover that improved sound or the meta. Honestly you don’t need meta for that fr. We have seen good responses already on r series

 

[thewas]

As shown in the white paper the biggest measurement differences come from all other changes than the metamaterial which is the only modification for which they don't provide comparison measurements, it is a shame many discussions are now reduced just to it, ignoring all other driver and crossover improvements.

 

[BrokenEnglishGuy]

Ls50M clearly shows improvements and are represented in the FR, it's more linear and better overall.

Also the previous LS50 doesn't use the same gen UNIQ as new the LS50M, technnical improvements are expected

12th vs 10th gen.

 

[Crosstalk]

As shown in the white paper the biggest measurement differences come from all other changes than the metamaterial which is the only modification for which they don't provide comparison measurements, it is a shame many discussions are now reduced just to it, ignoring all other driver and crossover improvements.

I saw in some forum someone modified the crossover of a regular ls50 to sound it neutral. So may be if kef changed the crossover that might have made it neutral already and then the what if meta is just marketing ? Wait it had better distortions right. So, that’s there

 

[thewas]

The original LS50 DIY crossover mod shown in German forums did make its frequency response smoother but as written in the white paper the drivers of the new Meta generation have different responses so the crossover had to be newly tuned from the start. The Meta has like you say also lower distortions plus an even better directivity than the original one even with the DIY crossover mod.

 

[Crosstalk]

The original LS50 DIY crossover mod shown in German forums did make its frequency response smoother but as written in the white paper the drivers of the new Meta generation have different responses so the crossover had to be newly tuned from the start. The Meta has like you say also lower distortions plus an even better directivity than the original one even with the DIY crossover mod.

Yes but end of the day final output only matters.

 

[bo_knows]

Yes but end of the day final output only matters.

Correct, and that final output of the speaker with the metamaterial will have 99% of energy from the back wave absorbed within the frequency range of the absorber. IMHO, this is a checkmark for engineers and they don't have to worry about this item any longer and can move on to different challenges. A simple, elegant, and cheap solution in comparison to a long aluminum tube(s) that protrude out of the speaker enclosure or sit on top. Now, the real question is, what was the absorption percentage before with the traditional materials used? And how audible is that delta? I would think it is and would love to have metamaterial in my speakers. Btw, I'm not sure that the use of metamaterial will show readily in the fr response. I would think it would maybe show up in some distortion measurements. I'm not an acoustician or speaker engineer so I don't know for sure but I know from personal experience that when you use absorption in the room, it may or may not drastically change room measured fr (depending on the amount of absorption and frequency range) but it will definitely eliminate slap echo (RT60) which you can easily hear. I would think that compared to the speaker/room interaction scenario, metamaterial will make your front wall (behind the speakers) disappear within the absorption range.

 

[pablolie]

Ls50M clearly shows improvements and are represented in the FR, it's more linear and better overall.

Also the previous LS50 doesn't use the same gen UNIQ as new the LS50M, technnical improvements are expected

12th vs 10th gen.

Never disputed that. Question is how audible the improvements really are. To each their own - here are the Stereophile measurements...

KEF LS50 Meta loudspeaker Measurements

Sidebar 3: Measurements I used DRA Labs' MLSSA system and a calibrated DPA 4006 microphone to measure the KEF LS50's frequency response in the farfield, and an Earthworks QTC-40 for the nearfield and spatially averaged room responses. My estimate of the LS50 Meta's voltage sensitivity was...

www.stereophile.com

They seem to indicate very small differences, and that's also spelled out throughout. But we'll all interpret it differently in the end.

To me at least, such small differences don't justify an upgrade. Another aspect to consider is behavior combined with a well-paired sub, which is probably going to result in further reducing distortion (even though the LS50 has always measured well there) and is not captured in any measurement.

 

[Descartes]

Could one of the experts in this forum superimpose the measurements for the LS50 on top of the LS50 Meta to see the differences!

 

[BrokenEnglishGuy]

Could one of the experts in this forum superimpose the measurements for the LS50 on top of the LS50 Meta to see the differences!

Already in this thread, it's a very clear difference

Correct, and that final output on speaker with the metamaterial will have 99% of deconstructive back wave absorbed within the frequency range of the absorber. IMHO, this is a checkmark for engineers and they don't have to worry about this item any longer and can move on to different challenges. A simple, elegant, and cheap solution in comparison to a long aluminum tube(s) that protrude out of the speaker enclosure or sit on top. Now, the real question is, what was the absorption percentage before with the traditional materials used? And how audible is that delta? I would think it is and would love to have metamaterial in my speakers. Btw, I'm not sure that the use of metamaterial will show readily in the fr response. I would think it would maybe show up in some distortion measurements. I'm not an acoustician or speaker engineer so I don't know for sure but I know from personal experience that when you use absorption in the room, it may or may not drastically change room measured fr (depending on the amount of absorption and frequency range) but it will definitely eliminate slap echo (RT60) which you can easily hear. I would think that compared to the speaker/room interaction scenario, metamaterial will make your front wall (behind the speakers) disappear within the absorption range.

Hmm

But the R series from 2018 and References series have a layering design, the UNIQ have it's own chamber, because the ls50 are port speaker it's not compatible with the layering design

 

[BrokenEnglishGuy]

To me at least, such small differences don't justify an upgrade.

To me the whole indsutry needs to change, actually the speakers are kind of the same always.

Why in 2020 speakers companys still doesn't give 20hz-20khz?

Even the Kef reference meta, are still 2x 6.5'' + ports, the typical design.

I will find more insteresting when kef going to make a Mini kef blade at 2000-4000 USD.., maybe 2030 lol
but that is asking too much, most of companys still don't get right their FR or get tons of distortion in critical places, sometimes companys launch models with even worse distortion than his old design, at least Kef get right the directivity-fr-distortion thing..