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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

hardisj

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Erin ran a pair of the R300 (IIRC) drivers in a car system awhile back.

Yep.

IMG_5801.jpg










And when I removed them from the car, I moved them to a DIY tower design using Scanspeak 10" revelator woofers.. (low woofer position to help combat the Allison effect)

IMG_0417.jpg
 

JD_Spoon

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In case anyone is interested, I just this morning got some pictures of the finished construction, pre-stain/lacquer stands that are being constructed to support my Reference 4c L/R speaker pair. They're constructed to permit filling the base with dampening material and set with mounting hardware underneath to support a set of isoAcoustics Gaia II feet. I'm not really concerned with their purported isolation capabilities, especially given that they're on hardwood flooring over a slab foundation, but I do like the fact that they will allow me to fine-tune the height, level, and angle properties of the setup.

20220131_064944.jpg

20220131_064952.jpg
 

Miker 1102

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Imo if you don't need your speakers to play as loud, R3 series are close enough and you can save a ton of money. But then I wonder how the Q series do since they are cheaper still. My guess those will not be as good even at lower volumes.
I keep thinking about the q series and of this center is even 10 percent better for the price.
 

Spkrdctr

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That seems like a very insightful point, perhaps should be tested for voice intelligibility/clarity/authenticity at different angles in the listening test to see if this highlights itself as a problem.
That was a very good read. If you have a speaker (center channel especially) that does 300hz to 2khz very well, it will be a great center channel and voices will not be hard to hear. Mess up this vital portion of a center channel and you really have no reason to own that speaker! I think Amir should/could include this in all of his future center channel tests. Do a fairly close examination of the critical 300hz to 2khz region. So many movies are hard to hear the dialogue due to the other background sounds (poorly mixed movie). This critical region will help with that. Especially if it is slightly elevated. The Subwoofer and L/R will handle all the other frequencies with ease and are not focused on speech. I think it is a very important area for a center channel.
 

Nootmuskaatje

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I think it is a very important area for a center channel.
Is it? Having a dedicated setup is already pretty niche. What's even more niche, is having fully acoustically treated rooms. So even for most of us, a perfect speaker will never be perfect because of SBIR and our furniture. Room EQ within AVR's do a pretty decent job to fix those and non-perfect frequency responses.

Even if it room EQ isn't sufficient, it's often still much cheaper to buy a DSP and add some filters. Some EQ goes a long way. Which is also something Amir has stated a million times. Many reviews are left with a statement that the speaker/headphone sucks, but then some filters made them great.
 

JD_Spoon

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I keep thinking about the q series and of this center is even 10 percent better for the price.
From my own subjective listening perspective, while the Q family is generally of good quality for its price point, there were substantial differences between the clarity and overall sound of the Q950 and the R11 towers. The latter offered much higher overall sound quality across the spectrum of everything I listened to, making it easier to distinguish instruments, and brought them out much more clearly, especially in the lower frequencies. One example that comes to mind is that on a couple of blues songs, the Q950 allowed me to hear and distinguish the bassline clearly over some other price-equivalent towers that muddied him into the background, but the R11 towers let me clearly distinguish the pick-playing of the guitarist from the finger-picking of the bass player.

Frankly, I thought there was a notably greater difference in the quality jump from the R series over the Q series than there was when comparing the Reference to the R. How you extrapolate and judge the relative value of those quality jumps, OTOH, is a personal matter. For me, strictly from a sound quality perspective in home theater applications, I have and would not hesitate again to recommend spending ~$300 more to run a pair of R5 towers in a phantom center config over a Q950/Q650c trio.
 

Miker 1102

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From my own subjective listening perspective, while the Q family is generally of good quality for its price point, there were substantial differences between the clarity and overall sound of the Q950 and the R11 towers. The latter offered much higher overall sound quality across the spectrum of everything I listened to, making it easier to distinguish instruments, and brought them out much more clearly, especially in the lower frequencies. One example that comes to mind is that on a couple of blues songs, the Q950 allowed me to hear and distinguish the bassline clearly over some other price-equivalent towers that muddied him into the background, but the R11 towers let me clearly distinguish the pick-playing of the guitarist from the finger-picking of the bass player.

Frankly, I thought there was a notably greater difference in the quality jump from the R series over the Q series than there was when comparing the Reference to the R. How you extrapolate and judge the relative value of those quality jumps, OTOH, is a personal matter. For me, strictly from a sound quality perspective in home theater applications, I have and would not hesitate again to recommend spending ~$300 more to run a pair of R5 towers in a phantom center config over a Q950/Q650c

From my own subjective listening perspective, while the Q family is generally of good quality for its price point, there were substantial differences between the clarity and overall sound of the Q950 and the R11 towers. The latter offered much higher overall sound quality across the spectrum of everything I listened to, making it easier to distinguish instruments, and brought them out much more clearly, especially in the lower frequencies. One example that comes to mind is that on a couple of blues songs, the Q950 allowed me to hear and distinguish the bassline clearly over some other price-equivalent towers that muddied him into the background, but the R11 towers let me clearly distinguish the pick-playing of the guitarist from the finger-picking of the bass player.

Frankly, I thought there was a notably greater difference in the quality jump from the R series over the Q series than there was when comparing the Reference to the R. How you extrapolate and judge the relative value of those quality jumps, OTOH, is a personal matter. For me, strictly from a sound quality perspective in home theater applications, I have and would not hesitate again to recommend spending ~$300 more to run a pair of R5 towers in a phantom center config over a Q950/Q650c

From my own subjective listening perspective, while the Q family is generally of good quality for its price point, there were substantial differences between the clarity and overall sound of the Q950 and the R11 towers. The latter offered much higher overall sound quality across the spectrum of everything I listened to, making it easier to distinguish instruments, and brought them out much more clearly, especially in the lower frequencies. One example that comes to mind is that on a couple of blues songs, the Q950 allowed me to hear and distinguish the bassline clearly over some other price-equivalent towers that muddied him into the background, but the R11 towers let me clearly distinguish the pick-playing of the guitarist from the finger-picking of the bass player.

Frankly, I thought there was a notably greater difference in the quality jump from the R series over the Q series than there was when comparing the Reference to the R. How you extrapolate and judge the relative value of those quality jumps, OTOH, is a personal matter. For me, strictly from a sound quality perspective in home theater applications, I have and would not hesitate again to recommend spending ~$300 more to run a pair of R5 towers in a phantom center config over a Q950/Q650c trio.
I really appreciate that break down. I had made a trade for a pair of 150s that just sat in my basement and when we listened to them I was really impressed. My wife(miraculously) encouraged me to look at the line to replace my beloved omd mirage speakers. We came close to pulling the trigger on the q950/650. I saw the R series at the brick and mortar as well but I find it's so easy to overspend on audio. Great breakdown for the difference. There has never been a speaker my wife liked immediately the way she did with the KEFs.
 

Descartes

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This is a review and detailed measurements of the KEF Reference 4C Center home theater speaker. It was kindly purchased new by a member and drop shipped to me. 4C costs US $7,500.

View attachment 179847

Apology for using stock picture. Speaker weighs 100 pounds and I got interrupted mid-review with our home flooding so still in measurement room. I had finished the measurements though and hence this write up. You can't tell from above picture but this speaker is deep, very deep. The finish is gorgeous but I found a tiny blemish which was disappointing. Back bindings are custom tool metal ones and the best I have seen and felt. No question KEF has targeted high level of execution with this speaker.

A coaxial driver handles midrange and tweeter responsibility. Woofers then bring the bass along (3-way total).

Measurements that you are about to see were performed using the Klippel Near-field Scanner (NFS). This is a robotic measurement system that analyzes the speaker all around and is able (using advanced mathematics and dual scan) to subtract room reflections (so where I measure it doesn't matter). It also measures the speaker at close distance ("near-field") which sharply reduces the impact of room noise. Both of these factors enable testing in ordinary rooms yet results that can be more accurate than an anechoic chamber. In a nutshell, the measurements show the actual sound coming out of the speaker independent of the room.

Measurements are compliant with latest speaker research into what can predict the speaker preference and is standardized in CEA/CTA-2034 ANSI specifications. Likewise listening tests are performed per research that shows mono listening is much more revealing of differences between speakers than stereo or multichannel.

Reference axis was the center of the tweeter (aligned by eye). Measurement room was at 10 degrees C which may lower bass output a bit. I used a higher resolution scan than normal which turned out to not be necessary as the speaker is very well behaved in higher frequencies. Accuracy is better than 1% as a result in most of the frequency spectrum.

KEF 4C Measurements
Acoustic measurements can be grouped in a way that can be perceptually analyzed to determine how good a speaker is and how it can be used in a room. This so called spinorama shows us just about everything we need to know about the speaker with respect to tonality and some flaws:

View attachment 179848

While not ruler flan, on-axis response is very good. Even better is directivity index (dashed blue at the bottom) showing that important early reflections are similar to on-axis response which you can see better here:

View attachment 179849

Bass response is stepped down due to port tuning being low. We can see this in the near-field response:

View attachment 179850

Cabinet/port resonances are kept at bay so don't cause coloration in upper midrange as they usually do in ported speakers.

Predicted in-room response is excellent:
View attachment 179851

BTW, sensitivity is also excellent at 90 dB although you better have an amplifier that doesn't mind the very low impedance dip of just 2.9 ohm:

View attachment 179852

The quad bass drivers and capable mid-range translate into incredibly low distortion and power capability:

View attachment 179853
View attachment 179854

The biggest issue with the design of most center speakers is that the doubled up woofer/mid-woofer causes horizontal dispersion to narrow due to timing differential between them. Is that solved here with the coaxial mid-range/mid-woofer? Let's see:


View attachment 179855

View attachment 179856

Speaker is so wide that there is still good bit of distance between the woofers causing some cancellation. But generally, this is way better than most center speakers we have tested.

The vertical response though shows how good this could be if all the drivers were aligned horizontally:

View attachment 179857

For fan of timing analysis, here are the rest of the measurements of that type:
View attachment 179860
View attachment 179861


View attachment 179862

Listening Tests
I was in the process of wiring up the speaker to listen to it in the measurement lab when my worried wife ran into the room and said: "downstairs bathroom is flooding!" I rushed out to deal with that and have not had a chance to listen to the 4C yet. I hope to still get a chance to do so and report back.

Conclusions
The fit and finish, design and capabilities of the 4C clearly show that this is a very serious engineering effort by KEF to produce a highly capable center speaker. Physics of sound wavelengths still attack it a bit causing slight narrowing of directivity but otherwise, it is very hard to find fault with this speaker.

I am going to recommend the KEF 4C based on objective data and subjective look and feel of the unit. I expect it to be a super capable center speaker and a great one for 2-channel listening if you use it vertically.

-----------
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/
In a couple of weeks KEF is releasing v2.0 with meta material technology and additional modifications it will be interesting to see if they measure better?
 

Head_Unit

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my current working theory (that audyssey xt32 BBC dip is causing it
We turned that off in a previous configuration and were much happier. I won't get new hardware of Audyssey without the App. To be fair, I also added a very wide gentle 1 dB peak up around I forget-4k?-so not a pure change.
 

Head_Unit

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Makes me want to see what the Reference 1's, 3's, and 5's are capable of.

Don't think anyone mentioned how visually stunning it is.

Understand they also wall mount the Reference Series. Quite a look

ci5160-header.jpg
Hmmm...that looks like a concrete wall, in front of studs? They drilled out holes for the woofers? ha ha. I'd want the 4 woofer side models underneath as well just because what the heck.
 
Last edited:

Descartes

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This is a review and detailed measurements of the KEF Reference 4C Center home theater speaker. It was kindly purchased new by a member and drop shipped to me. 4C costs US $7,500.

View attachment 179847

Apology for using stock picture. Speaker weighs 100 pounds and I got interrupted mid-review with our home flooding so still in measurement room. I had finished the measurements though and hence this write up. You can't tell from above picture but this speaker is deep, very deep. The finish is gorgeous but I found a tiny blemish which was disappointing. Back bindings are custom tool metal ones and the best I have seen and felt. No question KEF has targeted high level of execution with this speaker.

A coaxial driver handles midrange and tweeter responsibility. Woofers then bring the bass along (3-way total).

Measurements that you are about to see were performed using the Klippel Near-field Scanner (NFS). This is a robotic measurement system that analyzes the speaker all around and is able (using advanced mathematics and dual scan) to subtract room reflections (so where I measure it doesn't matter). It also measures the speaker at close distance ("near-field") which sharply reduces the impact of room noise. Both of these factors enable testing in ordinary rooms yet results that can be more accurate than an anechoic chamber. In a nutshell, the measurements show the actual sound coming out of the speaker independent of the room.

Measurements are compliant with latest speaker research into what can predict the speaker preference and is standardized in CEA/CTA-2034 ANSI specifications. Likewise listening tests are performed per research that shows mono listening is much more revealing of differences between speakers than stereo or multichannel.

Reference axis was the center of the tweeter (aligned by eye). Measurement room was at 10 degrees C which may lower bass output a bit. I used a higher resolution scan than normal which turned out to not be necessary as the speaker is very well behaved in higher frequencies. Accuracy is better than 1% as a result in most of the frequency spectrum.

KEF 4C Measurements
Acoustic measurements can be grouped in a way that can be perceptually analyzed to determine how good a speaker is and how it can be used in a room. This so called spinorama shows us just about everything we need to know about the speaker with respect to tonality and some flaws:

View attachment 179848

While not ruler flan, on-axis response is very good. Even better is directivity index (dashed blue at the bottom) showing that important early reflections are similar to on-axis response which you can see better here:

View attachment 179849

Bass response is stepped down due to port tuning being low. We can see this in the near-field response:

View attachment 179850

Cabinet/port resonances are kept at bay so don't cause coloration in upper midrange as they usually do in ported speakers.

Predicted in-room response is excellent:
View attachment 179851

BTW, sensitivity is also excellent at 90 dB although you better have an amplifier that doesn't mind the very low impedance dip of just 2.9 ohm:

View attachment 179852

The quad bass drivers and capable mid-range translate into incredibly low distortion and power capability:

View attachment 179853
View attachment 179854

The biggest issue with the design of most center speakers is that the doubled up woofer/mid-woofer causes horizontal dispersion to narrow due to timing differential between them. Is that solved here with the coaxial mid-range/mid-woofer? Let's see:


View attachment 179855

View attachment 179856

Speaker is so wide that there is still good bit of distance between the woofers causing some cancellation. But generally, this is way better than most center speakers we have tested.

The vertical response though shows how good this could be if all the drivers were aligned horizontally:

View attachment 179857

For fan of timing analysis, here are the rest of the measurements of that type:
View attachment 179860
View attachment 179861


View attachment 179862

Listening Tests
I was in the process of wiring up the speaker to listen to it in the measurement lab when my worried wife ran into the room and said: "downstairs bathroom is flooding!" I rushed out to deal with that and have not had a chance to listen to the 4C yet. I hope to still get a chance to do so and report back.

Conclusions
The fit and finish, design and capabilities of the 4C clearly show that this is a very serious engineering effort by KEF to produce a highly capable center speaker. Physics of sound wavelengths still attack it a bit causing slight narrowing of directivity but otherwise, it is very hard to find fault with this speaker.

I am going to recommend the KEF 4C based on objective data and subjective look and feel of the unit. I expect it to be a super capable center speaker and a great one for 2-channel listening if you use it vertically.

-----------
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/
Do you think the new meta reference measure and sound better?
 

Descartes

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Makes me want to see what the Reference 1's, 3's, and 5's are capable of.

Don't think anyone mentioned how visually stunning it is.

Understand they also wall mount the Reference Series. Quite a look

ci5160-header.jpg
How do they measure? So much cheaper as well!
 

Descartes

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I believe that’s the in-wall models, Ci5160RL and Ci3160RL. At £5300 MSRP for the pictured trio somewhat more affordable! Certainly more so than the in-wall Reference Ci5160REF!

The in wall reference are honestly so overpriced!! Better stay in that house for twenty years to amortize the cost!
 
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