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KEF Reference 4C Review (Center Speaker)

Rate this speaker:

  • 1. Poor (headless panther)

    Votes: 5 1.5%
  • 2. Not terrible (postman panther)

    Votes: 6 1.9%
  • 3. Fine (happy panther)

    Votes: 73 22.5%
  • 4. Great (golfing panther)

    Votes: 240 74.1%

  • Total voters
    324

phoenixdogfan

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BTW, this looks like a nearly exact replica of a KEF Reference 5 which sells for $19k a pair. Same mid tweet unit by the looks of it and same MTM arrangement of 4 6.5" woofers. Only visual difference is it looks like a slightly shorter enclosure. Don't know about the crossover or the quality of the enclosure, but it would be interesting to have the Reference 5 spin for comparison. Would also be interesting to see if the preference score would change if the vertical and horizontal directivity measures were flipped.
 
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dshreter

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I have concerns that mid-range movement modulates the tweeter.
Sweeps will not measure this. Perhaps, combines sweep of mid-range with constant high frequency could be used to test for this.

- Rich
Wouldn’t the CSD show this?
 

JD_Spoon

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BTW, this looks like a nearly exact replica of a KEF Reference 5 which sells for $19k a pair. Same mid tweet unit by the looks of it and same MTM arrangement of 4 6.5" woofers. Only visual difference is it looks like a slightly shorter enclosure. Don't know about the crossover or the quality of the enclosure, but it would be interesting to have the Reference 5 spin for comparison. Would also be interesting to see if the preference score would change if the vertical and horizontal directivity measures were flipped.
The Reference 5 is 10" taller than the Reference 4c is wide, 12" if you add the plinth & feet. Otherwise, their dimensions are identical.
 
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amirm

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Crazy. Maybe they aimed to the non domestical cinema environment, which could accept this price.
This is not that expensive. There are a lot of home theaters that cost hundreds of thousands of dollars. Since the entire family can use and enjoy a home theater, budgets are routinely much healthier than a 2-channel music system. We used to have a reference theater at Madrona which would retail for $300K if you wanted one built. And we have built some for clients that cost even more.
 

dwkdnvr

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I agree, it measures great.

But I have to wonder, (being a DIY type of person) what drivers could be had for far less money, and for most intents imitate that performance.

$7,500 give you literally a THOUSAND dollars per driver, and $2,500 for crossover and box.....hmmmmmm....
The DIY version of this - assuming you anchor it with a coax driver - is basically decide what level of Kef driver you want to use and go buy a speaker to use the driver, and then add woofers of your choice. There really aren't any coax drivers available that are up to the standards of Kef, unfortunately.

If you wanted to do a bargain-basement version just to get a taste, you can get a single refurb Q150 speaker from A4L for $220 or so. Add in a pair of good cheap woofers like the Anarchy from diysoundgroup ($65 each) and work on the crossover. Would be an interesting and potentially rewarding project.

It also is unlikely to come anywhere close to the performance of the Reference 4C.

Or, you can just go down the line to the R2C at $1300 - basically the center channel version of the R3. Probably doesn't measure up to the 4C, but still likely to be a very good performer.
 

dshreter

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Erin's audio corner and others have measured this by measuring the tweeter FR with the midrange fully extended and fully retracted. Around 1db difference at some frequencies but that is not audible. I wouldn't lost sleep over it.
I believe you, but a point of interest, does it matter if the midrange is moving vs just extended? How did they extended the midrange, put a voltage across past the crossover?
 

voodooless

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Erin's audio corner and others have measured this by measuring the tweeter FR with the midrange fully extended and fully retracted. Around 1db difference at some frequencies but that is not audible. I wouldn't lost sleep over it.
That is not all. It also causes intermodulation to rise. This test will not measure that. It would be nice to include the multi tone test from the DAC reviews for speakers as well. It would clearly show intermodulation products. @amirm have you ever considered adding it to the default speaker test suite?
 
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amirm

amirm

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It would be nice to include the multi tone test from the DAC reviews for speakers as well. It would clearly show intermodulation products. @amirm have you ever considered adding it to the default speaker test suite?
Klippel charges a ton of money for multitone test module. In the past, I have used my Audio Precision for this but results were useless. Since frequency response is never the same between speakers, the levels of intermodulation distortion winds up being all over the place. With DACs, the frequency response is constant so it is easy to see level of distortion. Not with speakers.
 

phoenixdogfan

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The DIY version of this - assuming you anchor it with a coax driver - is basically decide what level of Kef driver you want to use and go buy a speaker to use the driver, and then add woofers of your choice. There really aren't any coax drivers available that are up to the standards of Kef, unfortunately.

If you wanted to do a bargain-basement version just to get a taste, you can get a single refurb Q150 speaker from A4L for $220 or so. Add in a pair of good cheap woofers like the Anarchy from diysoundgroup ($65 each) and work on the crossover. Would be an interesting and potentially rewarding project.

It also is unlikely to come anywhere close to the performance of the Reference 4C.

Or, you can just go down the line to the R2C at $1300 - basically the center channel version of the R3. Probably doesn't measure up to the 4C, but still likely to be a very good performer.
I was reading that someone ripped the Coax's out of something like a Q150 and put them in the dashboard of his Honda. He apparently really liked them. Might make that a project some day.
 

Mnyb

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It seems all new Kef share a similar shelf in the bass ? This ( to ) low port tuning , why is that a good idea .

Never had any speaker where I had to turn down the base ever in any room I used .

In the past decades i’ve always used room correction in the bass , but it tends to make the total bass level a little leaner
 

Descartes

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This is not that expensive. There are a lot of home theaters that cost hundreds of thousands of dollars. Since the entire family can use and enjoy a home theater, budgets are routinely much healthier than a 2-channel music system. We used to have a reference theater at Madrona which would retail for $300K if you wanted one built. And we have built some for clients that cost even more.
Is that what you have at home:eek: can I come and watch a movie please I will bring the popcorn
 

sifi36

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It seems all new Kef share a similar shelf in the bass ? This ( to ) low port tuning , why is that a good idea .

Never had any speaker where I had to turn down the base ever in any room I used .

In the past decades i’ve always used room correction in the bass , but it tends to make the total bass level a little leaner
As a British manufacturer, they are probably designing for significant room gain in the low frequencies. Our rooms tend to be smaller and the Reference are supposed to be placed as close 30cm from the front wall, according to the white paper LINK (a great read in my view, it references the work of Floyd Toole and shows one of the best spinoramas I’ve ever seen). They also tend to made from brick so in-room response tends to get boosted even more as compared to a timber framed one. The majority of Kef’s customers aren’t using subwoofers, EQ or bass management unfortunately due to audiophile dogma.

My love of this hobby came from listening to my uncle’s Reference 107 and subsequently (and currently) the 207, with matching centre and surrounds. It’s great to hear that my passion was ignited by a brand that takes the science and engineering of sound reproduction seriously!
 

thewas

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For centre channels or generally? It really does seem to have solved the "centre channel problem", but in terms of lefts & rights (and I guess surrounds) there are a number of good 2-way normal speakers that can fit the bill. It seems like coaxial is super-good for centres.
On left and rights the problem of the flawed directivity of most non-coaxial loudspeakers in one axis is usually just moved to the other (in this case vertical) axis. Of course there it is usually not as problematic and is also often questioned/discussed but if you can have perfection, why not getting it there too, also for the reason of better channel matching. Personally I don't want to miss such even directivity especially at nearfield listening, where imaging is also often superior due to the better "blending" of the drivers and early reflections (for example from desktop or mixing console surface) responses.
 

KMO

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Is the center driver (coaxial?) similar to the KEF LS50 driver?

Conceptually, yes. But the construction is somewhat different round the back. There's a presentation here in which you can see the LS50 (original), R series (2012), Reference and Blade drivers at 4:30.

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.

It looks like the "low distortion motor" is working, from the tests.
 

KMO

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As a British manufacturer, they are probably designing for significant room gain in the low frequencies.
Correct - that's what they do for most of their range. But they step it up for the Reference series. Jack Oclee-Brown discusses that here at 28:00. The Reference speakers come with a choice of two port lengths to let you adjust the tuning.

And the specs suggest that this includes the Reference 4c. Amir didn't mention a choice of port, but it looks like the long ports were in use.

Were there short ports in the box? There should have been.

From their Reference White Paper, the ports roughly give you these two performance choices relative to a sealed box. Long = blue, short = purple.

index.php
index.php
 
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abdo123

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I have concerns that mid-range movement modulates the tweeter.
Sweeps will not measure this. Perhaps, combines sweep of mid-range with constant high frequency could be used to test for this.

- Rich

the mid-range won't move if it's crossed at ~300Hz, at all.
 

KMO

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Nothing that I've seen as far as measurements anywhere for the Reference 4c; that was one of the main reasons why I sent mine to @amirm to have it tested. The horizontal orientation of the 4c trio was just one of the layout options mentioned in the product manual that came with the speakers.
You're not just thinking of this rather generic "don't put it them in silly places" diagram, are you? That's just telling you to put it on a shelf or stand, not on the floor.

1642582606097.png


And, actually, with no outrigger feet for balance, they probably couldn't ever suggest upright use on basic product safety grounds. That would be overriding any sound quality considerations.
 
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KMO

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Unfortunately, I do not, I'm using another pair of Reference 4c stood vertically in their stead. I did not have the authorization to stretch my budget far enough to pay the ~$28k for the full monty of that series. Truth be told, I only got the 4c trio because they were discounted significantly.

Seeing them sell pairs of Reference 4c speakers as they're doing certainly does give the impression they're trying to clear stock. I think Amir may just have helped with that :)

Maybe they've seen less demand than expected for high-end expensive dedicated centres...
 
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