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KEF R11 Meta Tower Speaker Review

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    Votes: 5 1.0%
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    Votes: 7 1.5%
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amirm

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This is a review, listening tests, EQ and detailed measurements of the KEF R11 Meta floorstanding speaker. It was sent to me by the company and costs US $3250 each.
KEF R11 Meta Floorstanding Tower Stereo Speaker Review.jpg

The R11 Meta is gorgeous looking with high gloss finish and cabinet that has been shrunk as much as possible to basically hug the drivers. The coax center driver is the star of the show carrying most of the audible band from 200 Hz up (see measurement below). I was impressed with the engineering that went into binding terminal of all things:
KEF R11 Meta Floorstanding Tower Stereo Speaker binding posts Review.jpg


With a turn of a knob, you connect the bass to the coaxial and vice versa! No jumpers here. Even the cardboard that the speaker came in has clever features like plastic that you pinch and it releases the sides of the box so you can get it out easier. First class execution all around.

KEF R11 Meta Speaker Measurements
As usual we start with our Klippel NFS robotic measurements of frequency response with acoustic center set to center of coaxial driver and grill left out (as well as port plug):
KEF R11 Meta Floorstanding Tower Stereo Speaker frequency response measurement.png

I sent out the measurement to KEF and correlation was excellent with their measurements. Their response was a bit smoother than mine but otherwise showed the same dip around 1.2 kHz and dip in bass response. Company explained that the former is diffraction related and goes away off axis and bass shelving was doing was done to accommodate room gain. I will check for this in listening tests later. For now, we can admire the nice directivity which is highlighted in off-axis response that is smooth and sloping down as we want to see it:
KEF R11 Meta Floorstanding Tower Stereo Speaker early window frequency response measurement.png


Very nice. Simulating room response we get:
KEF R11 Meta Floorstanding Tower Stereo Speaker predicted in-room frequency response measurement.png

The dip is not as pronounced now which is good.

I forgot to measure the port response but here is one of the woofers and coaxial driver:
KEF R11 Meta Floorstanding Tower Stereo Speaker Driver Response measurement.png

Even in good speakers I am used to seeing woofer break up/resonances but here, that is so suppressed. Credit goes to the coaxial driver which goes so low, allowing earlier roll off of the woofer response.

Coaxial driver brings uniform directivity and that is precisely what we see:
KEF R11 Meta Floorstanding Tower Stereo Speaker horizontal beam width measurement.png
KEF R11 Meta Floorstanding Tower Stereo Speaker horizontal directivity measurement.png

KEF R11 Meta Floorstanding Tower Stereo Speaker vertical directivity measurement.png


While competing waveguide solutions manage similar behavior horizontally, vertically they are usually a mess. Not so here. Vertical response of the R11 Meta is almost as good as horizontal -- a nice bonus!

Those quad woofers work to bring ease of bass and SPL handling:
KEF R11 Meta Floorstanding Tower Stereo Speaker THD percentage distortion measurement.png

KEF R11 Meta Floorstanding Tower Stereo Speaker THD distortion measurement.png


It sounded clean even during sweeps. So I decided to push it to 102 dBSPL:
KEF R11 Meta Floorstanding Tower Stereo Speaker 102 dBSPL THD distortion measurement.png

This is why you buy a high-performance tower speaker folks instead of bookshelf. Same amount of floor space but far better handling of music at elevated levels.

Some of you worry about the misnamed speaker "compression" so here are the three responses adjusted to land on top of each other, with proper vertical scale:
KEF R11 Meta Floorstanding Tower Stereo Speaker Level Sweep Frequency Response measurement.png

There is just no audible consequence as a result of going from 86 dBSPL all the way up to 102 dBSPL.

Impedance minimum falls at higher frequencies making it easier to handle as music is not as loud there:
KEF R11 Meta Floorstanding Tower Stereo Speaker impedance and phase measurement.png


There are some resonances as is the case with just about every speaker I measure:
KEF R11 Meta Floorstanding Tower Stereo Speaker CSD Waterfall response measurement.png

And here is the step function for fans of that:
KEF R11 Meta Floorstanding Tower Stereo Speaker Step Response measurement.png


KEF R11 Meta Listening Tests and Equalization
Due to heaviness of the speaker, I tested the R11 Meta in our living room as you see in the review picture. This is a massive open floor space with ceiling at some 25 feet. Speaker was away from the rear wall to the tune of 5 to 6 feet (about 2 meters). Stock sound seemed "accurate" for the lack of a better term. I was curious what effect EQ would have on the two things that were visible in on-axis response: dip at 1.2 kHz and bass shelving:
KEF R11 Meta Floorstanding Tower Stereo Speaker Equalization EQ Parametric.png

I started with the 1.2 KHz (Band 2). This gave female voices more brilliance and pulled them out in front of the speaker a bit. Depending on the clip I played, I could see how someone would prefer it without EQ, while others would want it with that small correction. It was a trade off between sounding a bit bright (with EQ) vs a bit recessed (stock).

I then dialed in the bass response with that boost. I was prepared for some distortion but nothing remotely was audible in that front. Instead, I was greeted with glorious, deep bass that was substantially more rewarding than stock response. What's more it helped to balance the overall tonality with the 1.2 kHz filter, no longer having that tad brightness effect.

I cranked up my amplifier to 0dB reference and started to play track after track. Every piece of music was glorious. Deep, deep bass that was clean as a whistle. Upper range response was delightful while not being accentuated at all. With my wife and dogs around, my testing especially at these playback levels is usually limited but I was enjoying the speaker so much I kept going. Next thing I know, our female dog is worried, running to my wife to hold her. And the male dog coming to me giving me that look of: "what are these loud sounds???" After they did this three times I decided to sadly quit.

Let me summarize it for you: the stock tuning is designed to not remotely offend. The shelving in bass will mean even if there are significant room modes, speaker will not get boomy as I routinely hear from flat response speakers. And the small dip at 1.2 kHz means it will never sound sharp either even if the recording is such. In that regard, I would call the R11 Meta tuning "conservative." There may indeed by something to this tuning as starting point. Since we must measure the response and EQ in bass anyway, we can make the correction I did. But for those who don't, they will get a better response. So the choices here seem wise even though I like very much preferred the filtering I applied (especially in bass).

Conclusions
We expect excellence, objectively optimized response from KEF speakers and we have that in R11 Meta. My experience with budget coaxial designs is that they give up power handling which to me is a poor trade off. Not here. The R11 Meta has excellent bass handling with very low distortion allowing me to EQ it with no degradation as far as distortion of playback ability. There is a bit of room left here in there for enthusiasts who want the optimal performance to get there with EQ. Result was that even in our living room with many hard surfaces and large space to boot, a single R11 Meta roared to action, delivering optimal and super enjoyable response on every reference track I threw at it. Science and excellent engineering works!

I am happy to recommend the KEF R11 Meta speaker. Not only does it perform well, it is well priced as well.

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As always, questions, comments, recommendations, etc. are welcome.

Any donations are much appreciated using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/
 

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Not bad, not bad. @jackocleebrown

Now people will finally understand why there's reason a bookshelf speaker sounds better than your bluetooth speaker the size of a carton of milk, and what the floorstander with multiple larger woofers offers. You, me, @amirm , @Sean Olive know that we can't just put it down a like a frequency chart eg. CTA2034A, or Preference rating.
Needs more research! @1 hour 12 05 secs

 
Last edited:
@amirm can you please measure FR to 60kHz

To show what John Atkinson calls "oil can resonance" of metal tweeters
 
And the small dip at 1.2 kHz means it will never sound sharp either even if the recording is such.
That's a bit of a long shot.. :D
Anyways, looks like a really great speaker and I'm glad to see the inclusion compression sweeps, altho stepped sines would be better for this (especially for active speakers).
@amirm is there a quick and easy way in the AP software to normalize these to the reference response and zoom in a bit more? That would make it a little easier to read and compare.
 
Looks like the center speaker I need. With it of course turned sideways.
The vertical response is remarkably good for a passive array of this size. That little coax is doing a ton of heavy lifting, to keep distortion low on that little unit operating from 200hz up is very nice work by KEF.

$6500 for two of these strikes me as a pretty good deal - isn't this their biggest/best speaker before the ls60/blade things?
 
I may pick these up as a game end speaker some day. I already purchased the Buchardt A10 so no big purchases for a while. Was hoping for these measurements, thanks Amirm!
 
Very nice result :)

For some reason the bass shelving is optional in the reference series via exchange of port inserts , but not in r series ?
It’s the only thing I’m not fond of in r series, but for good bass you have eq and sub anyway.

R series also have port bungs for thier larger models for the purpose of taming the bass even further.
Do they recon that us plebs that can afford R lives in small rooms and are of fragile constitution :)

I bougth a pair of LS60 instead of R7 and dual KC92 .......
 
@amirm is there a quick and easy way in the AP software to normalize these to the reference response and zoom in a bit more? That would make it a little easier to read and compare.
I am not using AP for these tests. It is all done by Klippel. I use the same 50 dB scale as in the frequency response graph so we don't lose sight of what we are looking at. Zooming in makes little sense as the measurements have noise in them and such zooming will exaggerate differences that may not be audible at all.
 
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