Kef blade 2 meta frequency response

[sigbergaudio]

Looks a bit dark actually, compared to stuff like the F208 and 8341A:
View attachment 255936

Personally I find 6-7dB drop to be the sweet spot, so I would likely find the Genelec to be a tad bright, and possibly the Kef sliiiiightly dark.


Here is an in-room response of a speaker that is voiced with more midbass lift than the Blade 2 (with a sub taking over at 100hz). Notice that even with that, the 100-300hz area is still a bit soft compared to the rest. This is not atypical.

 

[dogmamann]

Personally I find 6-7dB drop to be the sweet spot, so I would likely find the Genelec to be a tad bright, and possibly the Kef sliiiiightly dark.


Here is an in-room response of a speaker that is voiced with more midbass lift than the Blade 2 (with a sub taking over at 100hz). Notice that even with that, the 100-300hz area is still a bit soft compared to the rest. This is not atypical.
View attachment 256029

Again personal preferences. I felt KEFs normally dark sounding but having enough life somehow. I am not alone with it. I undertand it’s intentional but it doesn’t mean its what everyone would like

 

[sigbergaudio]

Again personal preferences. I felt KEFs normally dark sounding but having enough life somehow. I am not alone with it. I undertand it’s intentional but it doesn’t mean its what everyone would like

But would more people like it than if it had a flat anechoic response? I guess we don't have any definitive way of knowing that.

As I wrote somewhere, we try to make our speakers sound as good as possible for most people in most rooms on most genres of music. I suspect Kef are trying for something similar. And if that is case, a flat anechoic response may not be the answer (I personally believe it isn't).

 

[abdo123]

A subtle reinforcement of this range sounds better, fuller and more accurate in all the rooms we've tested and across a wide range of music.

A subtle anything does not really sound "better" in my opinion, it sounds different. I need like at least a 3 to 4 dB difference so i can describe it with any adjective other than different.

So you might want to ask yourself whether the reinforcement you're adding is just adding more confusion to the cycle of confusion.

 

[thewas]

Also the target doesn't necessarily need to be a fully straight line, here for example the "experienced listeners" curve from Toole which possibly even fits closer to the one shown from Sigberg above as its flatter between 150-300 Hz.

Personally I prefer flat direct sound above transition frequency (even equalise my KEFs to it) and ideally look for loudspeakers which from their directivity then give the desired tonal balance in each room.

 

[Descartes]

Seriously how many people on this thread owns them or have listen to them?

 

[Sancus]

As I wrote somewhere, we try to make our speakers sound as good as possible for most people in most rooms on most genres of music. I suspect Kef are trying for something similar. And if that is case, a flat anechoic response may not be the answer (I personally believe it isn't).

There's a significant problem with this theory because Kef absolutely does not voice most of their speakers this way. If you look at the Reference or R series or LS50, they are mostly brighter than the LS60 or Blades.

I don't think this is a mistake, Kef is too competent to have done this by accident. But I don't really buy that they've just decided this voicing is better for all speakers all of a sudden.

 

[witwald]

And what is "neutral"? ...we also know that especially the 100-300Hz area suffers from several and often wide dips in the majority of rooms, due to reflections that are not present in an anechoic chamber. A subtle reinforcement of this range sounds better, fuller and more accurate in all the rooms we've tested and across a wide range of music.

Is it possible to flesh out what is meant by "subtle reinforcement"? What are the amplitude changes in dB going to be?

 

[sigbergaudio]

There's a significant problem with this theory because Kef absolutely does not voice most of their speakers this way. If you look at the Reference or R series or LS50, they are mostly brighter than the LS60 or Blades.

I don't think this is a mistake, Kef is too competent to have done this by accident. But I don't really buy that they've just decided this voicing is better for all speakers all of a sudden.

View attachment 257172

First of all this is an interesting discussion, thank you for participating. As you said it's hardly an accident, so there could be design goals and or / target audience considerations involved here. The LS50 Meta will likely be used in far smaller rooms for instance. And I suspect they also do listen to the speakers.

I'm also not sure if it's true that LS60 and Blade 2 are suddenly deviating from all the other Kef speakers. An example of another larger Kef speaker is the R11. I'd say that's quite similar to the voicing of the Blade 2 (this is 0-15-30). They both have around 2dB lift in the midbass area compared to the mid/upper mid range, similar to what we do.

Also as mentioned earlier (hopefully in this thread but at least elsewhere), it's difficult to understand exactly how speakers will sound in-room based on the graphs alone.
It would be extremely interesting to hear @jackocleebrown chip in on this discussion. Both on the voicing of the Blade 2 vs LS50 specifically, and in general on "deviation" from perfectly flat anehoic.

 

[sigbergaudio]

Is it possible to flesh out what is meant by "subtle reinforcement"? What are the amplitude changes in dB going to be?

The SBS.1 has a lift of roughly 2-2.5dB in the midbass compared to the midrange when measured on-axis anechoically. The Manta in its final tuning has yet to be measured in a Klippel (measurements due in February). To give an indication the total deviation will be well within +/-3dB for the Manta as well (the SBS.1 is +/-2.5dB).

 

[sigbergaudio]

Here's the Reference 5, similar slope there too:

 

[dogmamann]

So basically KEF has a “voicing” like other companies, it’s not similar to Genelec or Neumann. It’s more “polite”, as opposed to the misconception that it’s “Neutral”. It’s again another tuning to please some listeners, and like all speakers some would easily prefere another brand over it.

That house sound is what the company thinks what’s best. But it doesn’t mean it’s acceptable to everyone.

 

[sigbergaudio]

So basically KEF has a “voicing” like other companies, it’s not similar to Genelec or Neumann. It’s more “polite”, as opposed to the misconception that it’s “Neutral”. It’s again another tuning to please some listeners, and like all speakers some would easily prefere another brand over it.

That house sound is what the company thinks what’s best. But it doesn’t mean it’s acceptable to everyone.

This is based on the assumption that completely flat on-axis anechoic response is best in a domestic situation. For some reason everyone assumes this is so. But we don't really have a reliable reference or evidence to that fact.

 

[thewas]

The LS50 Meta are quite neutral at the listening window, when I switch on some filters to make them totally flat the difference is difficult to hear with most music. The bigger series are tuned a tad warmer though. The advantage of loudspeakers with smooth directivity is that someone can equalise them easily to any preferred target which can also vary depending on the music listened, older recordings sound often too bass shy when listened with modern room corrected systems as they were usually mixed without room correction.

 

[dogmamann]

The LS50 Meta are quite neutral at the listening window, when I switch on some filters to make them totally flat the difference is difficult to hear with most music. The bigger series are tuned a tad warmer though. The advantage of loudspeakers with smooth directivity is that someone can equalise them easily to any preferred target which can also vary depending on the music listened, older recordings sound often too bass shy when listened with modern room corrected systems as they were usually mixed without room correction.

Why someone cannot equalize a speaker with poor directly at the listening spot is something I never understood.

 

[thewas]

Why someone cannot equalize a speaker with poor directly at the listening spot is something I never understood.

You can but either you will have a coloured neutral direct sound, or a coloured reflected sound or a compromise of both which all give an inferior total result. The human perception prefers when the direct and reflected sounds are similar, you can read what Toole writes about the topic in the first link in my signature.

 

[tuga]

Yes, the bass region is overestimated on most such Stereophile plots, unfortunately it cannot be said though how much.

Around 6dB according to @John Atkinson :

The black trace below 300Hz in fig.3 shows the complex sum of the woofer and port outputs, taking acoustic phase into account, and rolls off with the usual 24dB/octave slope below the port tuning frequency. What is not seen in this graph, however, is the 6dB boost in the upper bass that results from the nearfield measurement technique, which assumes that the drive-unit is fixed in the center of a true infinite baffle; ie, one that extends to infinity in all directions.
https://www.stereophile.com/content/thiel-audio-scs4t-loudspeaker-measurements

Measuring Loudspeakers, Part Three Page 6 - Nearfield Responses
For published graphs, the loudspeaker's nearfield response is spliced to the farfield response in the 300Hz region. However, as pointed out in the Keele paper, the nearfield response assumes a 2-pi or half-space loading for the drive-units—close coupling to the room boundaries. This results in an apparent low-frequency boost in the resultant composite graph compared with a true anechoic response made of the same speaker. Given that a loudspeaker's woofer and port are always within a fraction of a wavelength from one boundary—the floor—and almost always less than one wavelength from three other boundaries—the walls and ceiling—below 100Hz or so, my experience has been that this does give a truer representation of a loudspeaker's real low-frequency performance than the anechoic response in all but extremely large rooms. Certainly, the loudspeakers I have auditioned that have true, flat anechoic extension to very low frequencies sound as if they have a somewhat exaggerated bass response—which is how they appear with a nearfield measurement.
https://www.stereophile.com/content/measuring-loudspeakers-part-three-page-6

 

[617]

You can but either you will have a coloured neutral direct sound, or a coloured reflected sound or a compromise of both which all give an inferior total result. The human perception prefers when the direct and reflected sounds are similar, you can read what Toole writes about the topic in the first link in my signature.

Correct, and often times the correction will make the indirect sound worse.

 

[dogmamann]

You can but either you will have a coloured neutral direct sound, or a coloured reflected sound or a compromise of both which all give an inferior total result. The human perception prefers when the direct and reflected sounds are similar, you can read what Toole writes about the topic in the first link in my signature.

On a speaker with good directivity, on applying an equalizer, we are essentially messing with the signal which goes to the speaker, meaning the direct sound has already become “inferior”(can’t we just call it altered?)

 

[sigbergaudio]

On a speaker with good directivity, on applying an equalizer, we are essentially messing with the signal which goes to the speaker, meaning the direct sound has already become “inferior”(can’t we just call it altered?)

To think of equalizing as "messing" and/or "inferior" is an opinion I wish we left behind in the 90s.