KEF R11 Meta Tower Speaker Review

[pjn]

If you can trust KEF's distortion specs, the R11 Meta should be a lot better than the R7 Meta:

R11 Meta:
View attachment 359293

R7 Meta:
View attachment 359294
R3 Meta somehow is a bit better than R7 Meta:
View attachment 359295

Yes, but 90dB is quite loud! The R7s are likely similar at a more modest level (i.e a smaller room - mine is < 2000cuft) - I have a pair and and measured distortion is neglible at my usual listening level - <75 dB. The R7s replace venerable and recapped Kef 104.2s which were briefly replaced by Kef LS50s (nasty distortion at about 90 Hz and now relegated to back channels).
I might add that I am extremely happy with the R7s

 

[DanielT]

Makes sense for music.

But for a movie, which reference level being at about 105 db, and sitting about 3 to 4 meters away... I'd really like to know if

1) the kef tweeter can keep up at 105 vs the 102 and at that long distance
2) for how long? Tweeter drive system will probably overheat and start compression... a long 5 minute drawn out action scene

Even for a movie I strongly doubt someone will have an long term average of 105 dB at the high frequency at the listening position continuously, as such would be VERY loud and also dangerous for the hearing, see also above plot for the spectrum, In my experience also the limit of almost all loudspeakers comes first in the bass, even the 4 x 6.5" woofers of the R11 Meta won't easily reach that level at 3-4 meters distance.
Here are distortion measurements of the old R11 non Meta, you see that rather the woofers suffer at 100 dB /1 m:

View attachment 359430
Source of above measurement: https://www.hegel.com/images/reviews/H190audiogermany.pdf

I'm only saying PA stuff, which are made to play at high SPL for longer periods of time. However, the disadvantage may then be that they automatically do not sound so good at lower or let's say normal or even high listening volumes (compared to good HiFi speakers such as the KEF R11). I know a generalization but still.

105 dB for a longer time=

 

[testp]

for each vs pair...
yeah but u have twice as many options

 

[peniku8]

Because the instrumentation there is very precise. Not so with acoustic measurements involving microphones, room noise, non-linearities, etc.

If the agreement between your own relative measurements is +-1.5dB due to room noise then you should stop publishing measurements until you fixed that. But it isn't. It's much higher and it seems to me like we're not on the same page with what we're talking about. Again, this is a relative measurement. Relative to your own measurement. The microphone could be an SM58 and the relative agreement between measurements like this will still be good.

When you have bass distortion in full percentage points, you could just be looking at distortion products and not anything remotely related to "compression." Such louder SPL tests could also cause room noises, etc. that distort the results.

This is not the case for active speakers with transparent limiters. The speaker could be 10dB into compression without audible distortion.
If you say the louder SPL tests cause room noise, which then muddies the results, then the distortion plots you publish are also incorrect. And then, if the room noise is an issue, is it too much to ask to fix those kind of issues? When you have a 100k measurement system? I'd volunteer to help with that task, if I wasn't on a different continent.

Really, if you care about audibility of frequency response due to SPL, then you must follow the 50 dB rule and not zoom in more. If I showed you even the best speaker response at 20 dB SPL, it would look bad.

Most of the other graphs are not adjusted to show the data in a psychoacoutically representative way, but to make the comparison between devices easier. If you went with this rule for everything, you'd have to stop publishing any kind of DAC distortion data, because it's all inaudible. Publishing data in a more user friendly format is always a good thing. And I'm repeating myself, but if someone misinterprets the data because it's easier to see in the graph than it is to hear in practice then I'm sure someone on here will step in and correct that misguided assumption.

 

[taotone]

I think this is one of the key elements - FR, distortion, etc. are very similar between R3 Meta and Reference 1 Meta at lower volumes, the better drivers (and cabinets presumably) hold up for an extra 10dB though.

The same thing can be seen comparing the Perlisten R to S series. They don't fall apart at higher volumes and hence it's only the reference lines that get the highest Dolby certifications.

 

[quattro98]

some people say that the drivers are the same even for the Blade model, other people say that the driver of the Reference / Blade use custom drivers with more sophisticated magnetic motors with a lot of expensive neodymium instead of ordinary ferrite

i have never seen photos of an A / B comparison of the dismounted coax driver of a R series / Reference series driver

There are cutaway renderings (they don't look like actual pictures to me) in the KEF white papers.

R series (link from https://us.kef.com/collections/r-series)

https://images.salsify.com/image/upload/s--_1LKGFsv--/new97sn5l4dtqcjadqeo.pdf

Reference series (link from https://us.kef.com/collections/the-reference) - same white paper for Blade & Reference

https://images.salsify.com/image/upload/s--Qrnn1ggt--/3bbba8edc0ece49267553efe3b4df80705d3a377.pdf

12th gen Uni-Q with MAT from R series

12th gen Uni-Q with MAT from Reference & Blade series

 

[Chromatischism]

I hate when companies and in this case reviewer states that speakers costs "3250 dollars each". Who the hell buys 1 or 3 of these ? Yes, there might be about 4 cases of that happening every decade but it's just plain stupid to put it that way. These cost 6500 and it should be stated in the review that way.

I hate speakers that are only priced in pairs. Sometimes we need 3 speakers.

 

[Chromatischism]

Yes, but 90dB is quite loud!

85 dB average is normal for home movies, with 95 dB peaks. Personally I don't want my speakers compressing or distorting to an audible degree at less than ~100 dB.

 

[Sokel]

There are cutaway renderings (they don't look like actual pictures to me) in the KEF white papers.

R series (link from https://us.kef.com/collections/r-series)

https://images.salsify.com/image/upload/s--_1LKGFsv--/new97sn5l4dtqcjadqeo.pdf

Reference series (link from https://us.kef.com/collections/the-reference) - same white paper for Blade & Reference

https://images.salsify.com/image/upload/s--Qrnn1ggt--/3bbba8edc0ece49267553efe3b4df80705d3a377.pdf

12th gen Uni-Q with MAT from R series
View attachment 359468
12th gen Uni-Q with MAT from Reference & Blade series
View attachment 359467

So the big difference is neodymium magnets for the higher series plus this:

 

[muad]

The shadow flare is the one big issue I have with the R series. I was hopeful it would be resolved with the meta refresh but alas it seems like that's not the case.

Thanks for the measurements!

They did fix it, it just needs to be pushed in.

When I had the R3, when you lined up the mid driver with the shadow flare the shadow flare would sit deeper than the front baffle itself, creating a circumferential ridge.

On the R3M, when pushed in (after shipping movement), the flare lines up with the mid driver and baffle almost perfectly.

 

[quattro98]

So the big difference is neodymium magnets for the higher series plus this:

View attachment 359469

The white papers provide some info, but we don’t know all of the differences and what improvements are attributed to what design and materials choices. The drivers, crossovers, and cabinets are all different.

 

[testp]

They did fix it, it just needs to be pushed in.

When I had the R3, when you lined up the mid driver with the shadow flare the shadow flare would sit deeper than the front baffle itself, creating a circumferential ridge.

On the R3M, when pushed in (after shipping movement), the flare lines up with the mid driver and baffle almost perfectly.

does the shadow flare decides to move back after a while or does it stay in?

 

[rs172]

Great Review.
I own a new pair of Kef r7 Meta, which sound great in my living room. When trying out the R11 they seamed to be a bit to much for my room. I suppose measurements of the R7 are not to different from 200Hz and above.

 

[Robbo99999]

Buchardt A700 are awfully competitive vs these.

They're 3000 Euro each, so probably ball park same price as the KEF R11. Amir hasn't reviewed the A700, but I saw the Erin review just now. The A700 reaches lower in the bass & without the sloped down bass shelf. His distortion plots are in a different format to Amir's, do you know how distortion compares?

 

[quattro98]

I think we're in a golden age for home sound reproduction. We have great choices in speakers, amplifiers, DACs, subwoofers, processors, room correction, and headphones. We benefit from excellent objective reviews which inform manufacturer and product selection. It's never been easier to obtain great sound without trial and error, trade-ins, and an endless stream of subjective reviews touting the next best thing.

 

[Chromatischism]

They're 3000 Euro each, so probably ball park same price as the KEF R11. Amir hasn't reviewed the A700, but I saw the Erin review just now. The A700 reaches lower in the bass & without the sloped down bass shelf. His distortion plots are in a different format to Amir's, do you know how distortion compares?

I'd have to dig in and try to interpret the measurements, if possible.

 

[KMO]

some people say that the drivers are the same even for the Blade model, other people say that the driver of the Reference / Blade use custom drivers with more sophisticated magnetic motors with a lot of expensive neodymium instead of ordinary ferrite

i have never seen photos of an A / B comparison of the dismounted coax driver of a R series / Reference series driver

I've posted this before, and it's somewhat outdated now, but here's a 2015 video where you can see the whole of the LS50 (original), R series (2012), Reference and Blade drivers at 4:30. These have all since been updated to be "Meta", and the Reference and Blade Meta now share a Uni-Q, but otherwise the general structural differences between R, LS50 and Reference remain.

Jack Oclee-Brown says there:

If you take a look at the R Series, the Reference and the Blade Uni-Qs, if you look at them from the front they have the same cone size, and that's intentional because we've optimised the size of that cone to work with the tweeter to give the best possible directivity match. But it means from the outside of the product you can't really see the differences in the design. It's only when you look at the back and you look at the motor system that you see now what makes a Blade driver better. So with the R series we have a relatively simple ferrite magnet system, but then stepping up to the Reference we use a neodymium, more powerful, low distortion motor. And then on to Blade we have again a more powerful neodymium magnet but this time with a much bigger 3-inch voice coil.

The 3-inch voice coil (nodal drive) for Blade has been dropped, presumably superseded by refinement of the "lossy interface" introduced in the 2018 R series, described in its white paper.

 

[anphex]

Sorry for noob question but what exactly is that "diffraction" effect there with that dip around 1,2 Khz? Is it the baffle step or and inherent thing of the coax driver?

 

[amirm]

Sorry for noob question but what exactly is that "diffraction" effect there with that dip around 1,2 Khz? Is it the baffle step or and inherent thing of the coax driver?

There is a sharp edge some place that acts like a little speaker out of phase causing some cancellation on axis. I don't know if this is the speaker edge or driver.

 

[testp]

maybe its the flare thing? althought if KEF said amir measurements looks right then maybe not