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Kef R3 Bookshelf Speaker Review (Erin's Audio Corner)

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hardisj

hardisj

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Was each driver measured independently (only one driver playing at a time) or is this somehow estimated from the speaker playing full range (which in my view is not the actual nearfield response of individual drive units)?

nearfield with all playing. so obviously you have the artifacts of this in the FR of each NF response. But it's enough to give you an idea of how the drivers behave in their passband.
 

MZKM

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Spinorama 22.gif


Do recall though that Amir has made improvements to his accuracy over time, I think the F328Be is when he optimized it as much as possible.

If going to 1 decimal place, the preference rating is the same at 6.5. Your sensitivity is up by 0.2dB (86.2dB vs 86.4dB), and your LFX is 1Hz higher (36Hz vs 37Hz). As for the frequency response window from the spec’d 58Hz-20kHz I get +/-2.9dB from Amir’s and +/-3.5dB from yours, that 9kHz bump being the obvious culprit.

I think this also shows what great consistency KEF has with their products (no clue if the cheaper Q series is as consistent).
 
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KEF speakers are not wide dispersion, so their soundstage isn’t large in a decently big room. However, in a narrow room the side wall reflections are stronger, so a narrow dispersion speaker may be preferred.

Quick question here and sorry if it's a daft one, I was always under the assumption that KEF's had a very wide dispersion of sound due to the Uni-Q array? Is this just a myth as I see on KEF's own website and report in various other forums that they disperse sound well? Has this been dispelled by the science?

For my own experience. When I demo'd the R11, B&W 702 and MA Gold 300 for me the Kefs had the widest soundstage by far (maybe the other were even narrower)
 

mtmpenn

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Just to pile on to this question, is there an agreed upon definition of wide versus narrow dispersion? Like X degrees at Y frequency (or averaged over Y-Z frequencies)?
 

Kachda

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Just to pile on to this question, is there an agreed upon definition of wide versus narrow dispersion? Like X degrees at Y frequency (or averaged over Y-Z frequencies)?
My understanding is that it's all relative.

Quick question here and sorry if it's a daft one, I was always under the assumption that KEF's had a very wide dispersion of sound due to the Uni-Q array? Is this just a myth as I see on KEF's own website and report in various other forums that they disperse sound well? Has this been dispelled by the science?

For my own experience. When I demo'd the R11, B&W 702 and MA Gold 300 for me the Kefs had the widest soundstage by far (maybe the other were even narrower)
It could be that B&W and MA have worse directivity ( not narrower) leading to a worse soundstage as reflected sound does not match direct sound. But this is speculation on my part.
 

mtmpenn

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My understanding is that it's all relative.

Sometimes it seems obvious to me, but for example when I compare Amir’s measurement of the R3 and his measurement of the Revel M16, I lack sufficient understanding to see what makes the revel wide and the kef narrow.
 

MZKM

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Quick question here and sorry if it's a daft one, I was always under the assumption that KEF's had a very wide dispersion of sound due to the Uni-Q array? Is this just a myth as I see on KEF's own website and report in various other forums that they disperse sound well? Has this been dispelled by the science?

For my own experience. When I demo'd the R11, B&W 702 and MA Gold 300 for me the Kefs had the widest soundstage by far (maybe the other were even narrower)
Those others may have FR & directivity issues, so the unevenness (especially around ~2kHz) could be what you heard.

Just look at the Directivity Index curves (the bottom 2 of a Spin graph), the lower the curve the wider the directivity.

KEF R3 (Amir & Erin):
index.php


B&W 607 S2:
index.php



The B&W is wider directivity in general. But the 3kHz dip means it won't sound as wide, but EQ that dip and it will.

And just for reference, I refer to dispersion as the raw performance and directivity as the normalized performance.
 
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Ratjones

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Those others may have FR & directivity issues, so the unevenness (especially around ~2kHz) could be what you heard.

Just look at the Directivity Index curves (the bottom 2 of a Spin graph), the lower the curve the wider the directivity.


The B&W is wider directivity in general. But the 3kHz dip means it won't sound as wide, but EQ that dip and it will.

And just for reference, I refer to dispersion as the raw performance and directivity as the normalized performance.

Thanks I get it now, here are a few questions if you don't mind making me none the wiser please, what does the delta between the SP DI and Early Reflections DI signify? I ask because in the above graphs the KEF has a wider gulf between it's Sound Power DI and Early Reflections DI compared to the B&W?

Does this mean that actually the KEFs disperse the sound pretty well in a living space due to the reflections that the listener gets? ie. the early reflection compensate for lack of directivity?

What is more significant, the Early Reflections DI or Sound Power DI? Sorry I did read all this on audioholics but I can't find much on the correlation between the two.

Pretty ironic, I have a KEF system coming next week built around the R series (R7, R2C and R3 Rears) I selected this system as I am listening along a 4 x 4 metre listening area and thought the keys dispersed the sound more equally when I went for demo's....
 

MZKM

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Thanks I get it now, here are a few questions if you don't mind making me none the wiser please, what does the delta between the SP DI and Early Reflections DI signify? I ask because in the above graphs the KEF has a wider gulf between it's Sound Power DI and Early Reflections DI compared to the B&W?

Does this mean that actually the KEFs disperse the sound pretty well in a living space due to the reflections that the listener gets? ie. the early reflection compensate for lack of directivity?

What is more significant, the Early Reflections DI or Sound Power DI? Sorry I did read all this on audioholics but I can't find much on the correlation between the two.

Pretty ironic, I have a KEF system coming next week built around the R series (R7, R2C and R3 Rears) I selected this system as I am listening along a 4 x 4 metre listening area and thought the keys dispersed the sound more equally when I went for demo's....
The curves are simply the difference between them and the listening window.

The more linear, the more consistent in soundstage width and the easier to EQ.
 

Ratjones

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The curves are simply the difference between them and the listening window.

The more linear, the more consistent in soundstage width and the easier to EQ.

Thanks and which is the more significant one? I’m struggling to understand the real world difference between the Sound Power DI and Early Reflections DI. I understand the early reflections DI is the more significant of the two?
 

MZKM

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Thanks and which is the more significant one? I’m struggling to understand the real world difference between the Sound Power DI and Early Reflections DI. I understand the early reflections DI is the more significant of the two?
Not fully sure, I’d say the ER DI becomes more important the closer you sit (so near-field) and Sound Power DI becomes more important the further you sit.
 

richard12511

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Thanks and which is the more significant one? I’m struggling to understand the real world difference between the Sound Power DI and Early Reflections DI. I understand the early reflections DI is the more significant of the two?

IMO, the ER DI curve is more significant. The SP DI includes radiation at all angles.
 

oursmagenta

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Hello,
I don't want to divert the thread too much, but I came across the Kef R11 measurements from Hi-Fi News
1619012402414.png

Could this dip around 1khz (and the weird pair matching) be related to the shadow flare ?
 

Alexanderc

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Hello,
I don't want to divert the thread too much, but I came across the Kef R11 measurements from Hi-Fi News
View attachment 125428
Could this dip around 1khz (and the weird pair matching) be related to the shadow flare ?
I believe we have evidence suggesting that it could be due to the shadow flare not being pushed all the way in--possibly more on one speaker than the other.
 

Alexanderc

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How accurate are Hi-Fi news measurements. All of the measurements I've seen from them seem to be somewhat more "off" than similar measurements from others.
I was only looking at the area around 1khz and comparing it to Erin's measurement from p. 1 of this thread. It looks quite similar to his measurement comparing different positions of the shadow flare.
Screen Shot 2021-04-22 at 11.11.23 AM.png
 
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hardisj

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Could this dip around 1khz (and the weird pair matching) be related to the shadow flare ?

I was only looking at the area around 1khz and comparing it to Erin's measurement from p. 1 of this thread. It looks quite similar to his measurement comparing different positions of the shadow flare.

Yep, I'd agree.
 
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