KEF Reference 2 meta Measurements and Review.

[bo_knows]

I wonder if the Kef R200c will get you most of the way there for a lot less money?

Wonder not, yes it will. I had Kef R200c for a long time and I enjoyed it very much. KEF Ref 2 meta is a much bigger speaker and has better dispersion and bass. I "had to buy it" in order to match my fronts. Nothing wrong with the original R series.

 

[Nuyes]

I can’t say I’m familiar with the concept of characteristic harmonic distortion, what is its practical meaning? It seems to be way lower than “classic” harmonic distortion. In the two plots above at 100Hz, for example, the THD is about 2% while the CHD is only about 0.37%. A missed marketing opportunity for manufacturers?

There are two limitations to measuring and calculating THD in a typical indoor environment.


1.
THD is calculated as HD / total energy (sum of 1st through 5th)(IEC), where only the linear distortion of the speaker should affect the response for the measurement to be valid.
(The effects of dips or peaks in the room environment must be excluded).

However, this is not perfectly possible, even in an anechoic chamber.


2.
The calculated THD is subjected to room effects once more in the related plot (dips and peaks).





So I use CHD for relative comparisons between speakers that are relatively free from these influences.


This is a way to calculate the average response between 200Hz and 10kHz, and then calculate the relative THD level of each.

This allows me to overcome the interference from point 2 above.


Of course, the impact of point 1 still exists, so it's hard to make head-to-head comparisons without assuming they're relative comparisons in the same environment.



I compensate for the limitations of LF by providing additional EHID, since most of the problems in indoor spaces are in LF, and HF can be overcome with moderate sound absorption.

 

[jbattman1016]

...
That's phenomenal for a 6.5-inch loudspeaker with bandwidth down to about 50Hz in a closed construction.

Is this to R2 or the R6 meta? The R2 only has 5 inch woofers.

Ignore me. I didn't realize that R2 and Reference 2 are different speakers.

 

[soerenssen]

Wonder not, yes it will. I had Kef R200c for a long time and I enjoyed it very much. KEF Ref 2 meta is a much bigger speaker and has better dispersion and bass. I "had to buy it" in order to match my fronts. Nothing wrong with the original R series.

I asked the dealer about matching the R6 Meta as center with my Reference 3 Meta speakers and they didn't recommend it. They obviously recommended going with the Reference 2 Meta or 4 Meta, for a better match.

Ref 3 Meta vs R6 Meta:
- aluminium drive units are the exact same size on both
- crossover frequencies of the R6 Meta are 500 Hz and 2.4 kHz
- crossover frequencies of the Reference 3 Meta are 450 Hz and 2.1 kHz

Ultimately I went with the R6, it's on its way, I will test the LCR combo in the following days and will share my thoughts under the R6 Meta topic. Just wanted to ask for your advice:
What would be an obvious sign of a mismatch? What should I look for?

 

[bo_knows]

I asked the dealer about matching the R6 Meta as center with my Reference 3 Meta speakers and they didn't recommend it. They obviously recommended going with the Reference 2 Meta or 4 Meta, for a better match.

Ref 3 Meta vs R6 Meta:
- aluminium drive units are the exact same size on both
- crossover frequencies of the R6 Meta are 500 Hz and 2.4 kHz
- crossover frequencies of the Reference 3 Meta are 450 Hz and 2.1 kHz

Ultimately I went with the R6, it's on its way, I will test the LCR combo in the following days and will share my thoughts under the R6 Meta topic. Just wanted to ask for your advice:
What would be an obvious sign of a mismatch? What should I look for?

I will make an assumption that Reference 2 Meta will have a wider dispersion (you can sit to each side of MLP and be ok) and lower distortion.

 

[sapphireracing]

Ultimately I went with the R6, it's on its way, I will test the LCR combo in the following days and will share my thoughts under the R6 Meta topic. Just wanted to ask for your advice:
What would be an obvious sign of a mismatch? What should I look for?

Look for a panning shot or quick cut when a voice quickly transitions from L/R to center of vice versa. The timbre of the voice should not change.

 

[soerenssen]

I will make an assumption that Reference 2 Meta will have a wider dispersion (you can sit to each side of MLP and be ok) and lower distortion.

Yes I expect such improvements, I just don't prioritize HT over music. As long as they are a good match, I'm fine with lesser components / measurements. Even an R3 + R2c combo with different woofer sizes is working fine for people, so I figured that combining the R center with the Ref series LR - having the same driver sizes - should be even better.

 

[soerenssen]

Look for a panning shot or quick cut when a voice quickly transitions from L/R to center of vice versa. The timbre of the voice should not change.

Is there a test track that you can recommend or a specific movie scene that could quickly show if there's something wrong?

 

[bo_knows]

Yes I expect such improvements, I just don't prioritize HT over music. As long as they are a good match, I'm fine with lesser components / measurements. Even an R3 + R2c combo with different woofer sizes is working fine for people, so I figured that combining the R center with the Ref series LR - having the same driver sizes - should be even better.

I don't foresee you having any issues using the R6 with Ref. Enjoy.

 

[soerenssen]

I don't foresee you having any issues using the R6 with Ref. Enjoy.

I just added a pair of Q350 as surrounds for 5.1. It will be a combination of Ref + R + Q.

 

[soerenssen]

I don't foresee you having any issues using the R6 with Ref. Enjoy.

I'm curious, can Audissey of Dirac correct such mismatches in the FR?

 

[Joey1167]

I just added a pair of Q350 as surrounds for 5.1. It will be a combination of Ref + R + Q.

Nothing wrong with this. I reached out to Kef and they stated in an email that their q,r and ref series are all timber matched! Should be fine!

 

[soerenssen]

Nothing wrong with this. I reached out to Kef and they stated in an email that their q,r and ref series are all timber matched! Should be fine!

I am happy with the Ref+R+Q combo. The woofer sizes are all matching (6.5 inch) and I couldn't detect/hear any issues during movies.

 

[exm]

If i have a subwoofer and listen to moderate volume, what are the reasons for me to still buy this over the R6 Meta? Hmm

As someone who owned:
- Reference 100c
- Reference 200c
- Reference 204/2c
- R2C
- Reference 4c
- Reference 2 Meta (my current speaker)

The Reference Uni-Q driver is in a different class. The transparency and openness (voices come alive) are out of this world. The reason I went from the Ref 204/2c to the R2c was because of downsizing (center was simply too big). I got an offer on the Ref 4c I couldn't refuse so I upgraded. Wow. Amazing. However, I realized the Ref 4c was too big (akin to the 204/2c) so I ended up working with my dealer on a great deal for the Ref 2 Meta. End-game for me, as long as I stay in my current house. To me, the Meta line is a marginal but noticeable improvement over the non-Meta (not sure if it's the Meta technology or simply better drivers and crossovers). Having said all of that, I'm sure that the R6 Meta is a fantastic center on its own. But the Reference is in a different class - but it's priced accordingly.

 

[aoaaron]

Is this better than Perlisten S series?

 

[Descartes]

Hello, long time no see!
I'm back with a center speaker from the KEF's Reference Series.


I took pictures when I was measuring it, but the pictures provided by the manufacturer are cleaner, so I'm posting it here.


View attachment 299376







Impedance

View attachment 299377
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Along with a smooth phase response, the linearity is not significantly distorted even at higher power (2.83 V).









Frequency Response

View attachment 299379
It has a largely flat FR characteristic, with a bass extension at about 49.3 Hz (-6 dB).
The bass roll-off falls on a gentle slope of about -14 dB/oct.

Thanks to the gentle slope, we can expect a beneficial room gain.






Nearfield Measurements
View attachment 299380









Directivity
View attachment 299381
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As is typical of KEF, it has fantastic directivity controls.
The horizontally placed units make it difficult to achieve uniform horizontal orientation, but KEF has managed to overcome this.


The asymmetry in vertical directivity in the highs after 10kHz is probably due to...


View attachment 299402


....the orientation of this lemon squeezer.










Beamwidth

View attachment 299385

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An even, smooth, controlled beamweed gives us peace of mind.
Thank you, KEF!











Polar plot
View attachment 299387


Due to the chunky mass of these speakers and the horizontally placed units, you can see that most of the sound is only radiating forward.








View attachment 299388

The polar plot of this speaker's vertical plane is closest to what I personally expect an ideal speaker to look like.

I love it.

Total Harmonic Distortion
View attachment 299389

View attachment 299390
Superclean.

The amount of distortion was so small that we had to increase the y-axis scale.








Equivalent Harmonic Input Distortion at 85dB SPL@1m

View attachment 299391


EHID may be new to some of you.

It corrects for the linear distortion of the measurement system (speaker-room-microphone) and provides THD related data as a result.

This allows you to measure THD free from the effects of the room, and it is very accurate.

However, due to the limitations of the method, it has the following constraints

1.It cannot see below F0 of the loudspeaker frequency response.

2.Linear distortions in the speaker itself, such as split vibration of the diaphragm or front baffle response, are also ignored, so it cannot be used for HF measurements.

Therefore, I only used 80 to 500 Hz for this measurement.


Anyway...

The performance is incredible!
Even at 80Hz, the THD is no more than 0.5%.










95dB SPL@1m

View attachment 299392

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View attachment 299394


Even with the output cranked up to 95dB SPL, there's quite a bit of defense against distortion.

This guy still has plenty of room to spare.









Multitone test
View attachment 299395



View attachment 299396


It doesn't even achieve a maximum of -35dB.
It hits -45 to 50 dB in almost all areas.
Again, that's tremendous performance.

View attachment 299397

I remeasured using only measurement signals above 80 Hz.
(The speaker and microphone positions are fixed, and this is all automated).


Interestingly, despite being a closed speaker, the MD was reduced in the HF as well as the LF.

I don't know why.





Multitone test(with multiple output levels)

View attachment 299398


View attachment 299399

Again, SuperClean.

Even at 96dB SPL@1m, it's only -35dB.

That's phenomenal for a 6.5-inch loudspeaker with bandwidth down to about 50Hz in a closed construction.






Compression test

View attachment 299400
Center speakers are often used in movie or gaming setups.

As such, they need to be able to handle momentary peaks.
If you want to see the limits of this loudspeaker, you might want to ruin your ears before you do.








HF -2dB knob

View attachment 299401
On the back of this speaker was a knob to attenuate the HF by -2dB.

And I measured the impact of that.





My personal opinion.


Given its beautiful appearance, ample bandwidth and performance, and neatly controlled directivity, I think this is one of the best center speakers out there.

Thank you so much for your review! Is it worth buying it’s big brother the Reference 4C Meta?

 

[exm]

Thank you so much for your review! Is it worth buying it’s big brother the Reference 4C Meta?

For what it's worth, I changed the Reference 4c to the Reference 2c Meta simply because my room wasn't big enough for the 4c. I don't hear any difference whatsover (80Hz crossover), with either the lack of 2 extra LF drivers as well as the addition of Meta technology.

 

[Descartes]

For what it's worth, I changed the Reference 4c to the Reference 2c Meta simply because my room wasn't big enough for the 4c. I don't hear any difference whatsover (80Hz crossover), with either the lack of 2 extra LF drivers as well as the addition of Meta technology.

How big is you room? Also what do you use for surround sound?

 

[exm]

How big is you room? Also what do you use for surround sound?

Not too big: 18x12ft. For side surround I am using the R3 Meta, and for heights 6xR8 Meta.

 

[Descartes]

Not too big: 18x12ft. For side surround I am using the R3 Meta, and for heights 6xR8 Meta.

How do you like the R8 as ATMOS speakers?