KEF and their slopping response, neutral ?!

[dogmamann]

Its ideal to have a flat on axis response and a slopping off axis response of the same pattern. KEF‘s on axis is slopping, compared to other speakers. Yet when I tried listening to Reference (non meta version) it sounded very harsh, bright, despite the 6 db sinking in treble region. Now I am trying to undertand if Kef guys knew their tweeters are somehow too sharp and wanted people not to hear it, so they rolled off the on axis. Still some people call it neutral. that’s no way neutral with that roll off, normally we wont put a cloth over cymbals before we listen to them!. Is there a reason other than this to have a rolled off on axis response?

 

[thewas]

Which exact model was it, as I don't see the old Reference sloping that much, only around 2-3 dB:

Source: https://assets.kef.com/pdf_doc/REF/REF-White-Paper-201219-LR.pdf

I personally don't find any newer KEF harsh, rather the opposite, which shows also that the perceived tonality depends on many factors, like room acoustics, placement, toe-in, recordings, listening distance, personal habituation and very important, how good the bass response at the listeners position is. In my experience when a well and neutral meas loudspeaker sounds bright the problem often lies on the other side of the frequency range, namely the bass region. Often there are SBIR related bass dips which make the total balance sound too lean where only a different placement of subwoofers can help, also the research of Toole and Olive has shown that even experienced listeners prefer few dB bass more than from a linear loudspeaker in a typical room:

Source: https://www.aes.org/e-lib/browse.cfm?elib=17839

 

[Blumlein 88]

So which response measurements are you going by?

Here on the R3 (which I know is not the Reference you are referring to) Amir shows what might be a bit bright balance.

KEF R3 Speaker Review

This is a review and detailed measurements of the KEF R3 stand-mount (bookshelf) speaker. It is on kind loan from a member who sent a pair to me at great cost (they come two in a box). The R3 costs US $1,999 for a pair. The R3 is an example of superb industrial design by KEF: It oozes...

www.audiosciencereview.com

 

[HarmonicTHD]

Its ideal to have a flat on axis response and a slopping off axis response of the same pattern. KEF‘s on axis is slopping, compared to other speakers. Yet when I tried listening to Reference (non meta version) it sounded very harsh, bright, despite the 6 db sinking in treble region. Now I am trying to undertand if Kef guys knew their tweeters are somehow too sharp and wanted people not to hear it, so they rolled off the on axis. Still some people call it neutral. that’s no way neutral with that roll off, normally we wont put a cloth over cymbals before we listen to them!. Is there a reason other than this to have a rolled off on axis response?

Do you have measurements of your listening room? If it is so obvious to you it should be easily measurable and can be EQed.

Btw. What 6dB roll off are you referring to? Which speaker exactly?

 

[MaxwellsEq]

Its ideal to have a flat on axis response and a slopping off axis response of the same pattern. KEF‘s on axis is slopping, compared to other speakers. Yet when I tried listening to Reference (non meta version) it sounded very harsh, bright, despite the 6 db sinking in treble region. Now I am trying to undertand if Kef guys knew their tweeters are somehow too sharp and wanted people not to hear it, so they rolled off the on axis. Still some people call it neutral. that’s no way neutral with that roll off, normally we wont put a cloth over cymbals before we listen to them!. Is there a reason other than this to have a rolled off on axis response?

You seem to be proposing that KEF know that all the tweeters they make are poor and so have modified the balance of all their speakers to cover this up.

I don't think you can make that sort of statement without presenting evidence that you have reliably measured all their speakers in all their variants.

 

[dogmamann]

Which exact model was it, as I don't see the old Reference sloping that much, only around 2-3 dB:

View attachment 281965
Source: https://assets.kef.com/pdf_doc/REF/REF-White-Paper-201219-LR.pdf

I personally don't find any newer KEF harsh, rather the opposite, which shows also that the perceived tonality depends on many factors, like room acoustics, placement, toe-in, recordings, listening distance, personal habituation and very important, how good the bass response at the listeners position is. In my experience when a well and neutral meas loudspeaker sounds bright the problem often lies on the other side of the frequency range, namely the bass region. Often there are SBIR related bass dips which make the total balance sound too lean where only a different placement of subwoofers can help, also the research of Toole and Olive has shown that even experienced listeners prefer few dB bass more than from a linear loudspeaker in a typical room:

View attachment 281967
Source: https://www.aes.org/e-lib/browse.cfm?elib=17839

To be honest, I didn’t feel there was a roll off of 6db. The details were all there but bit muted. But there was some megaphone effect on the Kef which I did not understand what part was making it sound like that. To me, reference 3 sounded Like the highest quality hyper detailed megaphone one can buy, paired with some high quality subs.

 

[dogmamann]

You seem to be proposing that KEF know that all the tweeters they make are poor and so have modified the balance of all their speakers to cover this up.
.

That’s my feeling. You are free to believe what you want to believe.

 

[bodhi]

You seem to be proposing that KEF know that all the tweeters they make are poor and so have modified the balance of all their speakers to cover this up.

I knew KEF were up to something. Decades of research and they just haven't managed decent tweeters, I would be covering that too!

 

[Talisman]

That’s my feeling. You are free to believe what you want to believe.

the sensations, if not related to measurements in the room, say absolutely nothing other than the fact that you didn't like them

 

[MaxwellsEq]

That’s my feeling. You are free to believe what you want to believe.

We all have opinions. You were wondering out loud whether KEF engineers have designed flawed tweeters and are using a downward slope to cover up this flaw. You need to do a better job then you have so far to justify your musings.

 

[dogmamann]

We all have opinions. You were wondering out loud whether KEF engineers have designed flawed tweeters and are using a downward slope to cover up this flaw. You need to do a better job then you have so far to justify your musings.

I posted three speaker’s graphs with sloping response, i dont know what else do you need to see they have roll off. But i would be happy to know the reason for this, and i hope it has nothing to do with some flaw. Measurements suggests they have very low distortion so, they could have set it up high without distorting. I wish the demo system had a eq to see if that shoutiness could have been corrected somehow.

End of the day, if someone can explain the on axis sloping response’s advantage that would be great.

 

[bodhi]

Last weekend I A/B'd the R5s with either natural roll off and EQ'd to flat. The flat version is just the usual showroom response where you at first hear so much more detail and sparkle, but after about 15 minutes I had my fill. But I'm pretty sure somebody would like the latter response better.

 

[dogmamann]

the sensations, if not related to measurements in the room, say absolutely nothing other than the fact that you didn't like them

Yes. You are right. I am only trying to undestand why it sounded the way it sounded

 

[dogmamann]

Last weekend I A/B'd the R5s with either natural roll off and EQ'd to flat. The flat version is just the usual showroom response where you at first hear so much more detail and sparkle, but after about 15 minutes I had my fill. But I'm pretty sure somebody would like the latter response better.

I listened to another on axis flat speaker and it sounded very smooth compared to the KEF. Kef despite the roll off was more shouty with mids somehow. I see nothing wrong in measurements. But i guess rolling of the top makes everything more “boxy”.

 

[dogmamann]

I knew KEF were up to something. Decades of research and they just haven't managed decent tweeters, I would be covering that too!

Or you can add meta material to sound like how other brands were sounding for ages.

 

[Ricardojoa]

Are those predicted in room response?

 

[goat76]

I think it may be KEF LS60 that got a sloping on-axis response.

 

[Purité Audio]

I don’t really see your point measured anechoically/klippel goi’d speakers have a ‘flat’ response, place them in a room and bass is reinforced and H/F reduced producing the gentle downward target that most domestic listeners prefer.
Keith

 

[dogmamann]

Are those predicted in room response?

Red is on axis. I am saying again, I didn’t feel the rolloff as aggressive as the graph says in real life though!

 

[dogmamann]

I don’t really see your point measured anechoically/klippel goi’d speakers have a ‘flat’ response, place them in a room and bass is reinforced and H/F reduced producing the gentle downward target that most domestic listeners prefer.
Keith

For example revels and other well measured speakers here have flat on axis and slopping off axis and predicted room responses. Kef has slopping on axis. Why?