KEF R11 Meta Tower Speaker Review

[Toothfairy]

Hi, new to this forum and i don't know if this is proper etiquette to talk about other brand in this forumn.

There seemed to be alot of loyalty or many fans to this brand. I am looking to buy a new pair of towers( I have a emotiva t2) and I learned about this model through YouTube and I was getting excited about this speaker. However as I read more and more I find myself thinking is it worth spending almost 7k on this pair or should I spend alot less on a arendal 1723 or even a martin Logan xt100. Are there anyone here that have experienced with arendal 1723 and is there a real difference between this and the r11. R11 build quality seemed be a little inferior to the 1723 but the esthetics of the r11 and the martin Logan xt 100 is much better looking imo. Can anyone offer their 2 cent about this. Thanks

 

[Vacceo]

"R&D Engineer - KEF" - that's a dangerous sig to have around here- someone might ask you a question! (I have two in mind already)

If I remember correctly, AOR did quite a nice amount of work on the LS60 on the part of the DSP. Dr. Oclee Brown is also with us and does not shy away from answering questions.

Do not be ashamed to ask, they do answer.

 

[cavedriver]

If I remember correctly, AOR did quite a nice amount of work on the LS60 on the part of the DSP. Dr. Oclee Brown is also with us and does not shy away from answering questions.

Do not be ashamed to ask, they do answer.

hehe, well, it certainly doesn't hurt although I'm not holding them to it expecting an answer. Let's try a two-parter:

The LS50 and Blades use rounded front baffles, while the R and Reference series use flat baffles with sharp-ish edges. Given the papers and study on baffle edges, diffraction, and just general baffle shape, ala Olson, but mostly as it affects diffraction, is there a reason why the curve of the LS50 or that of the blade isn't always better than the R/Reference flat baffles and curved baffles are just that hard/expensive to make, or is the R/Reference flat baffle actually comparable in performance, and if so, why? And part two- if you could extend these baffles to something say 2-3 feet wide, would the curvature of the LS50 be your starting place, or would it be more flat, ala R/Ref, or more curved, ala Blade? All this assumes passive with free crossover design and a minimum frequency range of the drivers on the face down to perhaps 200~300 Hz.

Now maybe if the rest of us can resist chiming in for just a day or two in hopes of a response from @AOR or anyone else from KEF (and like this post if you want to hear an answer), and then let loose

 

[MaxBuck]

Just listening to this album on my (non-Meta) R11s. Man, that string bass!

Decided I don't need subwoofers.

 

[napfkuchen]

Just listening to this album on my (non-Meta) R11s. Man, that string bass!
...
Decided I don't need subwoofers.

Then you were lucky with the room acoustics. The R11, still available new, costs about twice as much as the R3, and for the Meta models the price ratio is almost 1 to 3. With the price difference you can buy two subwoofers and in terms of sound (both in terms of SPL and bass performance) this will be another step forward. In my opinion the larger models are priced very unattractively.
Maybe the look also plays a role, tastes are different. I would always like the R3 with a suitable stand more.

 

[hollis]

Regarding the need for full towers like the R11 when you have subwoofer(s)...

With Dirac ART, this dilemma changes once again. I am going to move my R3 to surround duty and buy R11 for the front. With my home theater being almost a perfect cube, this will likely improve some of the nulls which are defying passive treatment. I can hope at least. ;-)

ART and 50hz-200hz speaker performance at reference SPL has been on my mind quite a bit as of late. Especially in a HT context with 85dB nominal and spikes above that.

I run a Storm ISR Fusion 20 and have been trying out a quite a few different speaker arrangements. This review of the R11 meta actually lead me to pull the trigger and grab some refurb non-meta R11s to the tune of $3200. I am evaluating them as both mains and as surrounds.

My results so far suggest that ART needs/wants quite substantial output from the surround channels in that bass to midbass range. More budget focused surrounds, such as my Ascend 340se mk1 really cant keep up if I try them as support channels to the mains. ART pushes them into distortion. My DIY HT12+ were fine in terms of distortion, but also, those really dont play much below 80hz so possibly ART wasnt being utilized to its full potential. Next tests will try R11 as mains, and then rotate them as sides.

Coaxial + tower + $1600 per speaker might make these astounding competent surround channels for an ART based setup. Mains could be meta, or full on Blades, or…. beyond….

 

[hollis]

Just listening to this album on my (non-Meta) R11s. Man, that string bass!

As a fellow non-Meta owners, yeah!
In 2ch, no DSP, straight out of the box mode. Holy hell do I agree. Just plug them in and go!

Decided I don't need subwoofers.

For that genre (and likely a few others) I 100% agree. Previously I was running multiple variations of subs + bookshelves. Subs to me are crucial, no way around them for my genres: EDM, Techno and Soundtracks. But, leaving sub+sat, I am finding with the R11 as full range I am enjoying some albums more than I ever have before. Rock is much more substantial and coherent. Peter Gabriel - US live, Porcupine Tree, Pearl Jam are each more satisfying than my previous listens. With the full range towers I know my bass does not go as deep, but, there are solid improvements I lack the audiophile vocab to correctly convey.

 

[AOR]

hehe, well, it certainly doesn't hurt although I'm not holding them to it expecting an answer. Let's try a two-parter:

The LS50 and Blades use rounded front baffles, while the R and Reference series use flat baffles with sharp-ish edges. Given the papers and study on baffle edges, diffraction, and just general baffle shape, ala Olson, but mostly as it affects diffraction, is there a reason why the curve of the LS50 or that of the blade isn't always better than the R/Reference flat baffles and curved baffles are just that hard/expensive to make, or is the R/Reference flat baffle actually comparable in performance, and if so, why? And part two- if you could extend these baffles to something say 2-3 feet wide, would the curvature of the LS50 be your starting place, or would it be more flat, ala R/Ref, or more curved, ala Blade? All this assumes passive with free crossover design and a minimum frequency range of the drivers on the face down to perhaps 200~300 Hz.

Now maybe if the rest of us can resist chiming in for just a day or two in hopes of a response from @AOR or anyone else from KEF (and like this post if you want to hear an answer), and then let loose

Hi Cavedriver,

I'll try to answer both of your questions...

Designing the physical features of a speaker is a three-way trade off: acoustic performance, aesthetics, and ease of manufacture/cost must all be held in balance.
"Traditional" hi-fi speakers tend to lean toward the boxy, cuboid form factor, as it satisfies both the aesthetic and the cost requirements, with the only compromise being a slightly worsened HF ripple due to the hard edge. Generally, this is not actually too bad in practise. A well designed crossover with well designed drivers can have a pretty decent response, even without a waveguide for the tweeter. (e.g. the Wharfedale 12.1 is one such example that doesn't show bad rippling. Ideal, no. Fine, definitely. https://www.erinsaudiocorner.com/loudspeakers/wharfedale_12_1/). The R and Reference series also include a "shadow flare" which is our name for an annular waveguide that sits outside the MF driver and continues the curvature of the MF cone to give a complete waveguide for the HF. This further minimised the diffraction effect.
The LS50 family and Blade family are probably what I would determine non-traditional loudspeakers, where the aesthetics can be more bold and the construction can be pushed further, so long as the extra expense serves both the form and the function. As such, both can incorporate a curved baffle.

In terms of larger baffles than we currently use, these have their own quirks to them; The baffle step can become a serious force that must be considered, and is in many ways more influential than the diffraction. At this scale, the exact geometry makes less of a difference for diffraction, and anything that isn't flat is quite expensive. If I were make a speaker with a baffle of that size (like some of the old JBL 4355), I'd make it flat. Rounding the corners would have a slight effect, but at the scale that you might be rounding the corners, the drivers probably "see" a 2pi environment...

 

[cavedriver]

If I were make a speaker with a baffle of that size (like some of the old JBL 4355), I'd make it flat. Rounding the corners would have a slight effect, but at the scale that you might be rounding the corners, the drivers probably "see" a 2pi environment...

Thanks for the great answer! I hadn't noticed the "shadow flare" on the R/Ref speakers. The second question was in part because I own some old Snells that are quite wide and quite flat (E/III's, 13" across) and partly because I'm thinking about making a Sonus Faber Stradivari clone using glued, stacked cutouts of either MDF or BB. That allows me to easily built a curved or flat surface with whatever edge transition I want to shoot for. Looking at the shadow flare, the waveguides on Revels, and then the different iterations of the Strad (original and current), it looks like SF is using different attempts at a shallow waveguide outside of the tweeter on each version, although I don't get the idea of the raised flat area on the newest G2 version. Lacking CAD and FEA experience I haven't decided exactly how to resolve this yet. The first priority was just getting the overall "curvature" of the baffle right where I'm trying to judge if it matters much or if I can just wing it (ahem). Current plan is close to the original Strad.

 

[mmshah]

How would these compare to the Reference 4c (no meta material)? I see them on sale at KEF currently for similar pricing to the R11 Metas.

Thanks

 

[SlothRock]

Does the glossy black pick up as much dust/fingerprints as a typical piano gloss finish or nah?