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KEF R3 meta Measurements

BrokenEnglishGuy

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My point is that there is no indication in ALL the other reviews on this site that narrower dispersion is better when you look at most of the highest scoring speakers. None of those speakers have dispersion this narrow, and in fact Amir often remarks that it is a positive that the dispersion is at least 50 degrees. And yet, here several people are suggesting that this speaker is superlative because it has narrow dispersion. I agree that it is a matter of rooms and preferences, but I do not agree that this speaker is broadly "better" than other speakers and in my experience speakers like this are difficult to position and have narrow sweet spots from which you can enjoy the stereo illusion, making them unsuitable for many listening rooms and environments. I think we all would agree that the dispersion should be "smooth", and if that is what Nuyes meant by "precise directional control" then I would agree, but I feel it should be noted that this speaker's dispersion width runs on the narrow side and that is not necessarily a positive. Frankly, I would not be buying this speaker because narrow sweet spots are such a pita.
Amir listening room isn't '' very small '' you know.. you have to find what fit better in YOUR space...
Genelec and Neumann are narrow dispersion, the thing is the new metas aren't that narrow now
 

pablolie

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I guess I’m misinformed, but I thought the in-room was in imprecise terms, the product of the spinorama data. Essentially the FR at the LP in a theoretical room. Not your room of course, but a consistent theoretical room from test to test. I look forward to being corrected on this.
My point is mainly that, if you keep changing the measurement protocol, it stops being useful in quick and direct comparisons. I have no doubt the R3 measures great, but I get no visual cues on how it compares with -say- an LS50 Meta, based on the available charts. The "in-room response" -even if the room is not the same as mine, however is the same as speakers are tested- allows me to get immediate visual cues.
 

mglobe

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E1141CE6-2DCE-4F50-8D53-E76323A0F6B0.png
 

JRS

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You can use PEQ/DSP to increase the system extension, which is what Neumann has done. There is no magic of any kind.
You give up total output levels and dynamic potential.
You will also have higher HD/IMD at higher SPL.
The trade makes sense if used in the nearfield where less total output is required.

If you want the R3(or KH150) to play very loudly in the farfield you have to reduce the demands on the 6.5" woofers. A 6db PEQ boost at 40hrz that works in the nearfield(or at low SPL in the far) will kill the speaker if higher SPL at fairfield distances is called upon.

The other option is to use a very high excursion 6.5" driver but then you give up sensitivity (and usually have to deal with the effects of a beefy surround). In an active mode this is fine as the woofer can just use a more powerful amp. In a passive then the total system will be low sensitivity which may or may not be a design issue.


It would be low sensitivity and likely need to use a passive radiator design to get a lower tuning in a small box. The weird surround of the Purifi is not really necessary in a 3-way. It would just need a well designed but very beefy surround.
The Purifi is designed for max-high performance, small 2-way application.

I have the BMR, it has a nice bass extension. For higher SPL the driver can not handle it.
For good output at SPL it should be used with a 70 or 80hrz high pass and subwoofer augmentation.
There is no benefit to crossing lower as the cabinet is large so it does not control the woofer well from 40-70hrz at higher output levels.

While I think many folks will be satisfied with the BMR's output levels, if you listen to bass heavy music at medium high to high levels in a decent sied space, the speaker will be very stressed.

Again remember that 2, 6.5" woofers only have the same output level of a comparable x-max 8.5" woofer. This can be considered essentially always the case. The SB acoustics woofers used in the BMR have between 3-6mm Xmax depending on the model/approach for generating specification. That means they output maximum SPL levels of a single 8.5" woofer with 3-6mm x-max. (and they will require more power to do it as the 8.5" will be usually be more sensitive all things being equal)

There is no magic of any kind.

Even the Purifi 6.5" has up to 10mm of x-max depending on the modeling approach for specing xmax. That means 2, 6.5" $440 purifi woofers ($880 for two) have the output levels of a typical, single 8.5" woofer with 8-10mm of xmax. That puts the Purifi in perspective eh'? Those are low sensitivity as well, though for the design type they are good.
This should put in perspective how much better any typical decent subwoofer is vs the extremely expensive Purifi. The Purif is a cool concept though and well engineered for what it is. It is just that what it is very niche and very expensive without enough real world gains in most cases.
I agree completely, and am not sure that moving from the ScanSpeak to SB Acoustics woofer was a change for the best. Or at least not so far as bass response is concerned.

You can't fool physics. Which is why my inner child is screaming for the Helios using what SBA is calling a 9.5 inch woofer, but needs to be taken with a grain of salt--more like 8.25 but enough stroke to eaual a pair of Purifi's.

The adult is saying you can't be serious--you sold for a song the tools you need in an effort to declutter. Both the finished in rosewood BMR and R3 meta could be here next week for right around 2k. No assembly rrequired! DYI 1800 + tools + materials + time + finding a good veneer guy (never tried and 300 dollars worth is probably not a good choice for first projects).
 

Newman

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Isn't a virtue for itself, the virtue is when you do the Mandatory acoustic treatment for get a good SQ, in narrow dispersion you don't need to put acoustic treatment in the sidewalls, while if you put a wide dispersion speaker in the small room you are going to need a lot of acoustic treatment.
According to Toole it's the exact opposite. I thought it was clear enough from the quotes I provided, that preference increases when the wide dispersion speakers are allowed to reflect off the side walls. Toole is not in favour of absorbing the first reflections off the side walls, because listeners prefer it when such reflections are allowed.

I think you have the wrong end of the stick here.
 
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BrokenEnglishGuy

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I think you have the wrong end of the stick here.
It wasn't me who delete part of my post, part of the post that '' support '' my claims.



To me, you are out of the context, in the post from audioholics that you provided but delete, there is this:
''where a narrow dispersion pattern is useful, such as instances where a greater control of the sound path is needed. ''
And this:

I have found that both wide dispersion speakers and narrow dispersion speakers can have excellent imaging as well as a sense of spaciousness and ambiance.
Also, someone in the same post point Tool to explain the narrow directivity thing and he stop to answer that thread. You shouldn't take that post seriously, is not even a finished conversation.
While you want to take this out of the context, but was contradictory with the audioholics post '' understanding loudspeaker measurements '':

I don't recall ever saying explicitly that narrow directivity has ANY special virtue
 

BrokenEnglishGuy

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It wasn't me who delete part of my post, part of the post that '' support '' my claims.



To me, you are out of the context, in the post from audioholics that you provided but delete, there is this:

And this:


Also, someone in the same post point Tool to explain the narrow directivity thing and he stop to answer that thread. You shouldn't take that post seriously, is not even a finished conversation.
While you want to take this out of the context, but was contradictory with the audioholics post '' understanding loudspeaker measurements '':
Uh im very sorry the post of audioholics was above, i was wrong here.


But anyway its contradictory
edit: that post was from another user, dam..
Too much internet for today i'll post later, i can't make a properly answer right now... i need to sleep
Sorry..
 
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DualTriode

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I don't have NFS, so I can't get the full Spinorama data.
Therefore, I'm focusing more on the other characteristics (ex: MD, Compression) that are worth noting.

It's a very difficult thing to score.
Especially when it comes to distortion, because the actual auditory feel of each distortion is different depending on its source and degree.

The same % of distortion can be annoying in different ways depending on what causes it.

There are even issues that don't show up at all in THD measurements.

For example...
Turbulent noise from ports, air leaks in the speaker box, and vibration from internal components are random noise and will not be detected by a THD measurement.

Also, intermodulation distortion in the speaker unit, distortion due to the Doppler effect, etc. are never detected by THD measurements.

However, these are important factors when we judge speaker performance by our 'ears'.
Hello,

I find it interesting that a single distortion mechanism can show up as Harmonic Distortion in a single tone FFT test, it can show up as THD in a frequency sweep (chirp), or show as side bands (Inter Modulation Distortion) in a multitone test. All caused by excursion of the voice coil through the B field.

Also what you may think of as random noise often will show up as spikes on a Rub and Buzz plot and as spikes on a frequency sweep.

Take a look at the referenced AES paper to see what Amplitude Distortion can do.

https://www.aes.org/tmpFiles/elib/20230224/12549.pdf

Also this paper:
https://www.aes.org/tmpFiles/elib/20230224/11286.pdf

Thanks DT
 
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ROOSKIE

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I guess I’m misinformed, but I thought the in-room was in imprecise terms, the product of the spinorama data. Essentially the FR at the LP in a theoretical room. Not your room of course, but a consistent theoretical room from test to test. I look forward to being corrected on this.
Howdy, I do think my post that you are responding to covers this. I think the basic answer is mixed into what I already stated.
Unfortunately, I am not exactly a good writer so it may be messy both there and here.

The 'Steady State Response/Equilibrium State', of a test signal captured by a single mic is not the frequency response of the speaker that you are hearing and perceiving as a listener. I can't break it all down quickly now but as you likely understand some key contributing elements= primary is the direct sound/listening window, secondary is the contribution of early reflections and then of those they need to be addressed differently. Such as horizontal early reflections are thought to be more important that ceiling and especially floor and so forth. Other contributing factors exist but this is just to show it gets complex fast (- but not too complex to manage with a Spin and a few Polars.)

It is confusing, I know.
The 'Predicted In Room Response', is essentially a prediction of the, 'Steady State in Room Measurement'. (It is created by examining, sound power, direct sound, & early arriving reflections)

Now the steady state in room measurement is not very indicative of what we hear. If it was, you could entirely skip all Klipple testing and all Anechoic chamber testing, grab a quick steady state in room and be done.

Toole, states in his book in section 5.6.2,
"The notion that a single curve resulting from sounds picked up by an omnidirectional microphone is an adequate representation of perceptions by two ears and brain is preposterous. It is related, but it is incomplete data.... a room curve tells us very little that is reliable about the loudspeaker itself... Listeners have demonstrated an uncanny ability to 'listen through' rooms and be able to identify key properties of loudspeaker performance. It is therefore clear that one must begin with comprehensive data on the loudspeakers in order to be confident about the sounds arriving at the listening position in a room."

The reality is that that measurement only hints at what you hear, which is far more complex. In Toole's book he touts it as a meaningful novelty. One that is interesting in that the Harman data collection strategy can come close to predicting it reasonably accurately and doing so is sorta cool. It is more of a way to check that the room is behaving as a typical room will. He never says that that data point is useful for much, nor is it representative of what we hear. Mainly it can confirm rooms issues and confirm that the speakers has a slowly tilting in room energy level by frequency, rising toward bass and falling toward treble which is an indication & property of a well designed speaker being used in a typical room(not an anechoic room by where the response would have zero tilt).

Spinorama, which is fairly detailed for many casually interested folks, is actually supposed to represent the practical limit of reduction in the data. (IMHO the Spinorama & the Polar Dispersion graphs are the minimum data to look at along with SPL capability)

You can not reduce the sound of the speaker down to the 'Predicted In Room Steady State Response' and understand more. In fact by being sort of tricked by that data points appearance and the name 'In-Room' - which grabs the user looking for simplicity and is relatable as we all have rooms, many are understanding less. ( So, there it is. The point I was making is that it seems many are using that data point and attempting to add value to it that it does not have. It has some very little value as a prediction and has some value as an actual measurement taken in your room in an effort to lightly troubleshoot room issues. And in the bass region is able to inform you of how to deal with room issues.)

Based on my interpretation of the information that I have encountered so far, it would proabily be fine to exclude the Predicted In Room chart forever, and at the same time as long as it is given proper weight (very minimal) keep it along.
That said I am a hobbiest mainly reading books and articles and listening to equipment for fun. Not a real expert by any means.

My point is mainly that, if you keep changing the measurement protocol, it stops being useful in quick and direct comparisons. I have no doubt the R3 measures great, but I get no visual cues on how it compares with -say- an LS50 Meta, based on the available charts. The "in-room response" -even if the room is not the same as mine, however is the same as speakers are tested- allows me to get immediate visual cues.
I think Amir will keep it but the dude doing this review has no Klipple NFS and so can't really create the chart.

Anyway, based on what I have stated above, hopefully you understand that I am saying any visual cue from that chart is a 'false positive' so to speak. It is not capable of representing what I believe you are hoping it does. There is essentially no point in comparing it speaker to speaker as it does not carry that value and ability. It does have some certain value just not in that way and was never intended to.
 
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Nuyes

Nuyes

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Hello,

I find it interesting that a single distortion mechanism can show up as Harmonic Distortion in a single tone FFT test, it can show up as THD in a frequency sweep (chirp), or show as side bands (Inter Modulation Distortion) in a multitone test. All caused by excursion of the voice coil through the B field.

Also what you may think of as random noise often will show up as spikes on a Rub and Buzz plot and as spikes on a frequency sweep.

Take a look at the referenced AES paper to see what Amplitude Distortion can do.

https://www.aes.org/tmpFiles/elib/20230224/12549.pdf

Also this paper:
https://www.aes.org/tmpFiles/elib/20230224/11286.pdf

Thanks DT
Hi~ Thank you so much for your kindness.

This is the first time I have seen the documents you have attached.
I will save them and read them calmly, thank you.

I also introduce you a good study material on speaker nonlinearity as a thank you.


If you want to learn more than just the basics, you can check out the link below.


Thanks for sharing your valuable information.
 

HarmonicTHD

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Hi~ Thank you so much for your kindness.

This is the first time I have seen the documents you have attached.
I will save them and read them calmly, thank you.

I also introduce you a good study material on speaker nonlinearity as a thank you.


If you want to learn more than just the basics, you can check out the link below.


Thanks for sharing your valuable information.
Thanks for sharing. I like the posters. Nicely summarized.
 

Vdrum

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I have a pair of Ls50 Meta and a KC92 subwoofer, powered by Nad M33. I‘m thinking about upgrading to the R3 Meta, mainly looking for an improvement on bass and sound stage. Would this upgrade produce any noticeable improvements? Tks
 

ROOSKIE

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I have a pair of Ls50 Meta and a KC92 subwoofer, powered by Nad M33. I‘m thinking about upgrading to the R3 Meta, mainly looking for an improvement on bass and sound stage. Would this upgrade produce any noticeable improvements? Tks
Hi, so 1st.
What size is your listening room & what is your listening distance?
Where is the single sub located?
Are currently high passing the LS50's (removing the bass from their signal path)& if so what frequency?
 

HarmonicTHD

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I have a pair of Ls50 Meta and a KC92 subwoofer, powered by Nad M33. I‘m thinking about upgrading to the R3 Meta, mainly looking for an improvement on bass and sound stage. Would this upgrade produce any noticeable improvements? Tks
Do you have the KC62 or the KF92? KC92 doesn’t exit. So if you happen to have the smaller KC consider upgrading to larger the KF first maybe. If you however already have the larger KF, then yes indeed the R3 might get you a bit smoother transition as they reach a bit lower.
 

mglobe

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I have a pair of Ls50 Meta and a KC92 subwoofer, powered by Nad M33. I‘m thinking about upgrading to the R3 Meta, mainly looking for an improvement on bass and sound stage. Would this upgrade produce any noticeable improvements? Tks
I don’t believe we have enough information yet to say for certain.
 

Thrill Killer

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A local shop is set to receive their allotment next Thursday(March 2nd). And are not accepting Pre-Orders. Dang, I want these. Can't get free until Friday 3/04. I hope some are still left. Another shop in the same city said they're only getting 2 prs. In Gloss Black only. I don't like that piano black look.

I just checked the KEF site. The R3 META are in stock with no tax and free s&h. But, only in black, eff that.
 
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Vdrum

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Hi, so 1st.
What size is your listening room & what is your listening distance?
Where is the single sub located?
Are currently high passing the LS50's (removing the bass from their signal path)& if so what frequency?
My room is around 35 sq meters, listening position 3 meters from speakers, subwoofer crossed over at 80hz and positioned next to the couch ( I know it is not ideal but that the only place available), the model is a KF92.
 

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