KEF R11 Meta Tower Speaker Review

[anphex]

Could you be more specific please?

Like filtering out this very specific distortion I have in one woofer, basically a resonance as if the woofer was causing something to vibrate internally, like a screw or something.

 

[staticV3]

Like filtering out this very specific distortion I have in one woofer, basically a resonance as if the woofer was causing something to vibrate internally, like a screw or something.

I'd try doing a manual frequency sweep to find the frequency which most clearly provokes this distortion. For this, you can use a simple tone generator like https://www.szynalski.com/tone-generator/

Then, copy the frequency into REW's tone generator and record it using the RTA function.

Do the same for both speakers, making sure to match the input voltage at the speaker terminals and the microphone position and distance, and you should see a difference in the resulting FFT graphs.

 

[anphex]

I'd try doing a manual frequency sweep to find the frequency which most clearly provokes this distortion. For this, you can use a simple tone generator like https://www.szynalski.com/tone-generator/

Then, copy the frequency into REW's tone generator and record it using the RTA function.

Do the same for both speakers, making sure to match the input voltage at the speaker terminals and the microphone position and distance, and you should see a difference in the resulting FFT graphs.

Thank you, I will try this once my dryer is finished in the background .

As for my other worry about a broken crossover, it seems that for KEF's Uni-Q drivers it's normal to the mid woofer to move even with low frequencies. At least this is what GPT4 confidently told me:

Me: Is it normal that the Uni-Q driver of KEF speakers also gets some bass frequencies? Does that make sense? I am used to crossovers cutting of the whole bass frequencies


GPT4: Yes, it's quite normal for the Uni-Q driver in KEF speakers to receive some bass frequencies, and it does make sense given the design and intended function of these speakers. Here’s a bit more detail on how this works:

1. Uni-Q Driver Technology: KEF's Uni-Q driver is a unique design where the tweeter (responsible for high frequencies) is placed in the center of the midrange driver (handling mid frequencies). This arrangement aims to improve sound dispersion and coherence, as it effectively aligns the acoustic centers of the tweeter and midrange, making the sound come from a single point in space.
2. Frequency Response and Crossover Design: In typical multi-driver speaker systems, a crossover is used to divide the audio signal into different frequency bands that are then sent to the appropriate drivers (e.g., lows to the woofer, mids to the midrange driver, and highs to the tweeter). However, in KEF’s Uni-Q design, while there is a crossover, it might not cut off all bass frequencies to the Uni-Q driver. This is because:
   • The midrange driver in the Uni-Q setup is designed to handle a wider range of frequencies than just midrange. It is capable of producing some lower frequencies effectively.
   • The presence of some bass frequencies in the midrange driver can enhance the overall richness and depth of the sound without causing distortion or undue stress on the driver, as long as it’s within the driver's operational bandwidth.
3. Advantages: Allowing the Uni-Q driver to handle a wider spectrum can lead to better integration of sound, especially in the critical crossover region between the bass and mid frequencies. This can make the speaker's sound more coherent and seamless across its frequency range.
4. Bass Management in the Speaker System: In many KEF systems, especially those including subwoofers or additional bass drivers, the crossover points and slopes are carefully chosen to ensure that the Uni-Q driver complements rather than competes with the bass frequencies produced by the larger drivers.

In conclusion, it makes sense for the Uni-Q driver to handle some bass frequencies to achieve a more integrated and natural sound presentation. The key is in how KEF designs its crossovers and drivers to work together optimally, leveraging the Uni-Q technology’s ability to create a point source-like emission of sound.

 

[dogmamann]

Even if I found the issue more or less by pure chance and using dedicated sine sweeps since the issue isn't audible on music usage and not even showing on measurements?

I doubt they do a full distortion measurement before leaving the factory. I saw these one of these videos and there they hooked up a sine generator and did a quick sweep and that was it. So I don't really blame them since it's really hidden.

Have a look at my home measurements before EQ. The distortion is ridiculously low still. R is the "broken" one.

Edit: Oh, if someone has an idea on how to visualize this specific distortion in REW, feel free to suggest.

Try sweeping the UNIQ alone on both keeping at the same spot! Also make sure you don’t alter the acoustics of the room while switching the speakers. Keep the speaker not under measurement in the same spot while not measuring and while measurement is going on you should also stand in the same spot.

Like filtering out this very specific distortion I have in one woofer, basically a resonance as if the woofer was causing something to vibrate internally, like a screw or something.

Also test the speakers with same channel of the amp. Probably your amp can be also a reason for the differences and you didn’t notice this earlier.

 

[MaxBuck]

I don't get buying a used speaker and then assuming that a discovered flaw is a factory problem rather than related to prior owner(s).

 

[dogmamann]

I am 99,99 % sure this is a misunderstanding and even if it wasn't, this would not be applicable in Germany. Warranty CAN NOT BE VOID on second hand market sales if the original invoice is available proving the original purchase date. Other than that KEF would have to proof TO ME in the first 6 months after purchase that it was a factory perfect speaker, which they can't really since the issue doesn't even appear on measurements, at least not in the precision I can produce at home.


I invite you to check out the issue: https://pics.anphex.one/s/5du36n0jtz/kef-reference-3-meta-faulty
Sorry for my super gibberish english. It was a on the fly video late after work .

Another mention: I have become so paranoid of getting accused of damaging stuff myself that I pack and unpack stuff on video only. I have the full unpackagin and assembly of the speaker in question on a 30 min video where it's absolutely proven that no slip of mine happened. There is also no dent in the packaging.

Of course there is always the possibility that the second hand seller """forgot""" to tell me but I wouldn't hesitate to pull the trigger on my legal insurance then after years of paying without any case.

Actually now this is tricky. KEF normally has 5 year warranty on their Reference and R line sold in Germany.

However according to KEF.de, warranty is not transferable. As per German law min of 2 year warranty is „forced“! So the moment you buy a used KEF Referwnce or R line product the best you can get is what is left of the two year warranty. If it’s already 2 years old, you are of your own

 

[Opal]

I don't get buying a used speaker and then assuming that a discovered flaw is a factory problem rather than related to prior owner(s).

Precisely. Why point fingers at KEF factory QC immediately without further investigation into the issues fully?

 

[ban25]

Precisely. Why point fingers at KEF factory QC immediately without further investigation into the issues fully?

I'm not even convinced there's an issue here TBH. All I see is an REW sweep for the two speakers, presumably in different positions. Any difference in frequency response could well be the result of room modes, particularly at the low end.

 

[anphex]

Actually now this is tricky. KEF normally has 5 year warranty on their Reference and R line sold in Germany.

However according to KEF.de, warranty is not transferable. As per German law min of 2 year warranty is „forced“! So the moment you buy a used KEF Referwnce or R line product the best you can get is what is left of the two year warranty. If it’s already 2 years old, you are of your own

To adress everyone before me @Opal @ban25 @dogmamann

The original purchase receipt is from 16.02.2024 and even if it was fake the Metas are avaiable since march 2022, so the chances are very very high that these fall below the average German warranty.

I excluded the prior owner doing anything wrong because the outside of the speaker as the packaging was meticulous. No dent, no split-off, not even a scratch. Plus I have all his personal data - who would give me that that readily if he knew he did something shady? I also excluded him being at fault because the issue is something you only notice in a very specific setup that most non-measurement-people would never even come close to try out. So it's very possible the issue was there at the beginning when it left the factory.
What people try to suggest is something in the range of "it is totally possible for a OLED TV mainboard to break during shipping of the TV while the package and panel are perfectly fine". It just does not make sense, sorry.

What's cool: You can remove the port easily due to the flexible port system right behind the woofer in question and I could use an endoscope and see if anything is loose. What I could see by eye inside was that everything is firm and solid.

Here's a more on-the-point video showing said resonance well audible, the 25 second video.

KEF Reference 3 Meta faulty

AI-Powered Photos App for the Decentralized Web

pics.anphex.one

Edit: @mod, maybe you could create a split off thread of the latter conversation up until the last review-related posts? Thread title suggstion "Weird KEF Reference 3 Meta resonance on second hand speaker".

 

[exm]

To adress everyone before me @Opal @ban25 @dogmamann

The original purchase receipt is from 16.02.2024 and even if it was fake the Metas are avaiable since march 2022, so the chances are very very high that these fall below the average German warranty.

I excluded the prior owner doing anything wrong because the outside of the speaker as the packaging was meticulous. No dent, no split-off, not even a scratch. Plus I have all his personal data - who would give me that that readily if he knew he did something shady? I also excluded him being at fault because the issue is something you only notice in a very specific setup that most non-measurement-people would never even come close to try out. So it's very possible the issue was there at the beginning when it left the factory.
What people try to suggest is something in the range of "it is totally possible for a OLED TV mainboard to break during shipping of the TV while the package and panel are perfectly fine". It just does not make sense, sorry.

What's cool: You can remove the port easily due to the flexible port system right behind the woofer in question and I could use an endoscope and see if anything is loose. What I could see by eye inside was that everything is firm and solid.

Here's a more on-the-point video showing said resonance well audible, the 25 second video.

KEF Reference 3 Meta faulty

AI-Powered Photos App for the Decentralized Web

pics.anphex.one

Edit: @mod, maybe you could create a split off thread of the latter conversation up until the last review-related posts? Thread title suggstion "Weird KEF Reference 3 Meta resonance on second hand speaker".

I looked at your video (love the color btw, I have the same one), but I'm not sure if there's anything wrong. At this point I would reach out to Kef GE or Kef UK support with your concerns and videos. I'm sure they can guide you to some other tests and further steps.

Maybe @davidbosch has some thoughts?

But please keep us posted!

 

[anphex]

I looked at your video (love the color btw, I have the same one), but I'm not sure if there's anything wrong. At this point I would reach out to Kef GE or Kef UK support with your concerns and videos. I'm sure they can guide you to some other tests and further steps.

Maybe @davidbosch has some thoughts?

But please keep us posted!

It's just that the lower woofer of one speaker has a needle resonance when playing about 33 Hz or 66 Hz very loudly. Already registered the speakers successfully on their website on my account (it even says warranty up until 2029) and I wrote them a letter with the links to the videos yesterday and now we wait.

 

[dogmamann]

It's just that the lower woofer of one speaker has a needle resonance when playing about 33 Hz or 66 Hz very loudly. Already registered the speakers successfully on their website on my account (it even says warranty up until 2029) and I wrote them a letter with the links to the videos yesterday and now we wait.

Wrong move ! Now you cannot even send it back to the Orginal owner. From my experience, these kind of things cannot be proven. The company normally says it’s working as expected and slight deviations from Orginal can be normal. They would slmply say your measurement method is not accurate. They will be very polite that eventually you will have to live with it! They would respond to you tomorrow most probably

 

[Paffi]

Wrong move ! Now you cannot even send it back to the Orginal owner. From my experience, these kind of things cannot be proven. The company normally says it’s working as expected and slight deviations from Orginal can be normal. They would slmply say your measurement method is not accurate. They will be very polite that eventually you will have to live with it! They would respond to you tomorrow most probably

I think the video with its sounds is pretty obvious, "not normal", you don´t think?

 

[anphex]

Got the answer from KEF. As expected, they are denying manufacturer warranty as per the ToS which was pretty clear since it's non transferrable, BUT they are considering a repair on goodwill in a service center. I appreciate this move already.

 

[dogmamann]

Got the answer from KEF. As expected, they are denying manufacturer warranty as per the ToS which was pretty clear since it's non transferrable, BUT they are considering a repair on goodwill in a service center. I appreciate this move already.

Great news! I bet all those who post “3 Jahre noch Garantie” in their ads in eBay Kleinanzeigen for KEF products have no clue about this ! This is a huge let down for someone who bought a wrong KEF product! No matter whether it’s one day old or 10 years old, you are on your own in case of a problem. To me, buying a used KEF unless the deal is steal(like yours) is not worth it.

This also, is a strong case to buy a new device or a demo device with the invoice in your name. Demo devices also get a good price cut. Some months back I saw 1 year R3’s sold on eBay.de for 950 euros. Considering the close out sale price of them were around 1000 euros at many places, that’s insane pricing for a device with no warranty left!

 

[anphex]

Great news! I bet all those who post “3 Jahre noch Garantie” in their ads in eBay Kleinanzeigen for KEF products have no clue about this ! This is a huge let down for someone who bought a wrong KEF product! No matter whether it’s one day old or 10 years old, you are on your own in case of a problem. To me, buying a used KEF unless the deal is steal(like yours) is not worth it.

This also, is a strong case to buy a new device or a demo device with the invoice in your name. Demo devices also get a good price cut. Some months back I saw 1 year R3’s sold on eBay.de for 950 euros. Considering the close out sale price of them were around 1000 euros at many places, that’s insane pricing for a device with no warranty left!

Exactly, if it hadn't been such a good deal, I would not be this calm. The warranty behaviour is unusual considering German standards but I can kind of see where they come from when they are shipping internationally in all continents - grey imports are a real problem. Questions is, how do some retailes get KEF speakers for sale but are not listed as Authorized Dealers?

 

[dogmamann]

Exactly, if it hadn't been such a good deal, I would not be this calm. The warranty behaviour is unusual considering German standards but I can kind of see where they come from when they are shipping internationally in all continents - grey imports are a real problem. Questions is, how do some retailes get KEF speakers for sale but are not listed as Authorized Dealers?

Probably they have connections with authorized dealers and they might be doing some adjustments among themselves to meet some sales target. Not every dealer has presence in every region.

 

[dogmamann]

Exactly, if it hadn't been such a good deal, I would not be this calm. The warranty behaviour is unusual considering German standards but I can kind of see where they come from when they are shipping internationally in all continents - grey imports are a real problem. Questions is, how do some retailes get KEF speakers for sale but are not listed as Authorized Dealers?

Actually if you go legal they will be pressed to provide you the warranty. They cannot make policies for themselves in Germany. If you have Rechtsschutz e please ask them how it works. Or you can consult the verbaucherzentrale if m not wrong to know your rights

 

[Vacceo]

Got the answer from KEF. As expected, they are denying manufacturer warranty as per the ToS which was pretty clear since it's non transferrable, BUT they are considering a repair on goodwill in a service center. I appreciate this move already.

Good on them and even better on you!
I hope you enjoy those speakers.

 

[anphex]

The "Keffies" are bound for a trip to the EU service center in Netherlands where it will show what kind of fault it was. What triggered this was that the second speaker now suddenly showed mid-woofer-only disortion from 1 to 4 Khz. Weird.

Oh also turns out the original original very first vendor is a certified KEF Dealer, so everything is fine and it raised the chance of goodwill a lot, while a repair on actual warranty is still on the table. So my chances are pretty high, kinda?