KEF Reference and Blade Meta announced, but where is the R Meta?????

[Vacceo]

If KEF is revisiting their products and updating them with reworked drivers, absorption technology and refined geometry (as they have been for decades), I really hope they give the, otherwise fantastic KSC92 subwoofer an XLR imput. Since they already have an APP, it´d be excelent if all those switches in the back get transformed into app functions to make a bit way for the XLR input.

 

[harkpabst]

However, a common misconception is that the crossover order is only due to the order used in the electrical filter. This is not the case, the true crossover order is the combination of both the electrical filters and the driver responses. This means that it's virtually impossible to achieve a true first order crossover and unfortunately means that this route to perfect time coherence is effectively closed.

You're so right (of course) and KEF engineers kindly told this to the world at least 6 years before you were even born (correct me if I'm wrong) with the introduction of "acoustic Butterworth filters"! It's 2022 now and some people still love to discuss the benefits of 1st order electrical filters instead of the most appropriate acoustical target function (which might or might not be 3rd order Butterworth depending on application).

It's not like this has been a "secret" before but Model 104aB has been the first commercial application crazily using the absolute correct technical term also for marketing. It's all been made possible by advanced analysis and design facilities way ahead of their time.

Funnily, almost the same can be said of the term meta material where some still incorrectly assume this to be an invention of KEF marketing.

 

[ahofer]

You're so right (of course) and KEF engineers kindly told this to the world at least 6 years before you were even born (correct me if I'm wrong) with the introduction of "acoustic Butterworth filters"! It's 2022 now and some people still love to discuss the benefits of 1st order electrical filters instead of the most appropriate acoustical target function (which might or might not be 3rd order Butterworth depending on application).

It's not like this has been a "secret" before but Model 104aB has been the first commercial application crazily using the absolute correct technical term also for marketing. It's all been made possible by advanced analysis and design facilities way ahead of their time.

Funnily, almost the same can be said of the term meta material where some still incorrectly assume this to be an invention of KEF marketing.

Interesting. Wasn't Thiel kind of built on that idea?

 

[harkpabst]

Interesting. Wasn't Thiel kind of built on that idea?

I suppose you are referring to former Thiel Audio? Could be, but they were founded in 1977, so after KEF Model 104aB hit the market.

I believe (but won't bet on it) that Thiel wasn't well known in Europe before like the late 1980s (or maybe even early 1990s). At least I certainly missed much of their history. I mostly think of them as paying much attention to time aligned drivers, but that's just me.

 

[ahofer]

I suppose you are referring to former Thiel Audio? Could be, but they were founded in 1977, so after KEF Model 104aB hit the market.

I believe (but won't bet on it) that Thiel wasn't well known in Europe before like the late 1980s (or maybe even early 1990s). At least I certainly missed much of their history. I mostly think of them as paying much attention to time aligned drivers, but that's just me.

time-aligned drivers and first order crossovers. https://www.stereophile.com/content/thiel-cs2-2-loudspeaker-first-order-filters

 

[BrokenEnglishGuy]

Why Kef only use Ports instead of big passive radiators?

Passive radiators doesn't work better against the wall?

 

[harkpabst]

time-aligned drivers and first order crossovers. https://www.stereophile.com/content/thiel-cs2-2-loudspeaker-first-order-filters

Since you mentioned it I had to look it up and also ended up with a find on stereophile.com: In their review of the CS3.6 they state that "the crossover is a true acoustic first-order (6dB/octave) type", though. As laid out by @jackocleebrown this is pretty much possible, maybe unless you opt for a 5- or 6-way design, which leads to more problems than it solves.

By now I cannot imagine any serious speaker manufacturer (read: those who don't compare their products with musical instruments) not paying attention to the acoustic slope formed by the driver (in it's cabinet) and the applied filter. Not so much when it comes to hobbyist, even though the required tool set is available for little money. From my point of view the real change brought up by KEF has been the mindset on how to design a speaker. Designers had already been aware of the fact that text book filters do not work (for many reasons). But the key idea behind acoustic Butterworth filters was to not only take measurements of real drivers in real enclosures but to actively aim after a well defined target response for all drivers inside and outside of the pass band instead of starting with generic filters and then tweaking them until the overall response fits (somehow).

However, back in the late 1970s/early 1980s KEF 3rd order aB filters more often than not consisted of 3rd order electrical filters that were optimized to give a clean 3rd order acoustic slope. This is different from more current designs where they would rather use the least steep electrical filters to reach the desired (individual) response. Technology has advanced a lot and today they surely have much more control over the natural roll-off of their drivers. Maybe one can say that Thiel and KEF may have come from different directions tackling a common goal.

Most of this is history now, Thiel for sure is. But speaker design to this day is still about dealing with compromises. Putting your finger on just one point (like selling "non-cheesy" boutique parts) is very easy and can even grant you a cult entourage, but it's rarely the way to real progress.

 

[harkpabst]

Why Kef only use Port instead of big passive radiators?

Passive radiators doesn't work better against the wall?

I cannot speak for KEF but from my experience the reasoning behind using passive radiators usually has little to do with how close you can place a speaker against a wall. In oversimplified terms the potential advantage of passive radiators is the absence of port resonances and port chuffing. One major downside is reduced efficiency (plus costs, mechanical complexity and so on).

KEF decided to address those topics with optimized port geometry and flaring (pretty common) and soft (yet acoustically impermeable) material used as part of the port wall (not so common).

If you keep a distance of 3 or 4 inches to the wall I would not expect a port to behave any worse than a passive radiator. If you really want to design a speaker for use straight against the wall you have to go with a front ported design (or a closed box) anyway.

 

[ahofer]

Since you mentioned it I had to look it up and also ended up with a find on stereophile.com: In their review of the CS3.6 they state that "the crossover is a true acoustic first-order (6dB/octave) type", though. As laid out by @jackocleebrown this is pretty much possible, maybe unless you opt for a 5- or 6-way design, which leads to more problems than it solves.

did you mean to say "impossible"?

I had 3.6s from 1994 to 2018, and really enjoyed them. They made it easy to listen for hours on end, something I never could do with my Magnepans (which isn't indicative of anything in particular re crossover claims.)

 

[harkpabst]

did you mean to say "impossible"?

Good catch, of course that's what I meant to say. Too late to edit my post now, so thanks for the clarifying hint.

I had 3.6s from 1994 to 2018, and really enjoyed them. They made it easy to listen for hours on end, something I never could do with my Magnepans (which isn't indicative of anything in particular re crossover claims.)

At least it indicates there was something right with the entire design.

 

[Vacceo]

I have never powered my current set of IQ´s with a good amp and a modern AVR/Processor. My next step is going for a good Hypex or Purifi amp for them so they have headroom in spades. My setup currently runs on Audyssey from 2008, so anything would be an important step up in terms of room EQ.

I wonder how huge could be the change from these veterans to something along the lines of an R series, with the same room and the same setup I currently have (11.2). I really love how they sound, so the logic step is keeping it KEF as the directivity, dispersion and reflections will, hopefully, stay fairly similar.

 

[Vacceo]

I had a long past eying the Blades since they released. I love the fact that they were inspired by Brancusi (I love his sculptures), they were designed and manufactured by the guys who did the speakers I have been using for quite some time (started with Cresta, moved to IQ) and had a sound that I like quite probably because it is the one I am used to.

I have finally been able to listen to the Blade 2 meta and the experience was extremelly interesting. I didn´t really know what to expect because the only super high end speaker I have listened to was a B&W Nautilus a long time ago, and we all know memory is a terrible advisor when comparing.

The way I´d compare my current IQ7´s to the Blades is similar to Eddie Hall or Hafthor Bjornsson deadlifting compared to me deadlifting: same movements, same principles, same goal but everything moving several orders of magnitude better.

The only thing I regret about leastening to these speakers is that I´ll probably never be able to afford them. That´s why I´d love KEF to recover the style or their old (and my current) IQ´s, with their curvy shape and tickle down not just the excellence of the drivers or the metamaterial, but also part of the geometry and the self-cancelling woofers (which are on the KS subwoofers).

 

[Descartes]

I had a long past eying the Blades since they released. I love the fact that they were inspired by Brancusi (I love his sculptures), they were designed and manufactured by the guys who did the speakers I have been using for quite some time (started with Cresta, moved to IQ) and had a sound that I like quite probably because it is the one I am used to.

I have finally been able to listen to the Blade 2 meta and the experience was extremelly interesting. I didn´t really know what to expect because the only super high end speaker I have listened to was a B&W Nautilus a long time ago, and we all know memory is a terrible advisor when comparing.

The way I´d compare my current IQ7´s to the Blades is similar to Eddie Hall or Hafthor Bjornsson deadlifting compared to me deadlifting: same movements, same principles, same goal but everything moving several orders of magnitude better.

The only thing I regret about leastening to these speakers is that I´ll probably never be able to afford them. That´s why I´d love KEF to recover the style or their old (and my current) IQ´s, with their curvy shape and tickle down not just the excellence of the drivers or the metamaterial, but also part of the geometry and the self-cancelling woofers (which are on the KS subwoofers).

Where did you hear them?

 

[Vacceo]

Where did you hear them?

In a coworker´s living room. No perfectly planned show room.

 

[Descartes]

In a coworker´s living room. No perfectly planned show room.

Very nice!

 

[Vacceo]

Now, the interesting thing would be to have the measurements for the Blade 2 metas I listened to and compare side by side to the IQ7´s.

Perception beyond audition matters to render judgement, and I do not trust it to be fair at all. Subjectively, my brain is yelling that the Blades have everything to sound better: the aesthetics, the age, the capacity to get louder, damn, even the color. However, the sense of everything coming at you from the same place is clearly present on both pairs of speakers. Both employ a coaxial mid woofer and tweeter, but that basic premise and the manufacturer is all they share.

All in all, I can say that it is the first time I have listened to Emperor´s I am The Black Wizards with such level of reproduction quality. Carcass, Bolt Thrower and Benediction followed, because well, the Blades were made in the UK, so why not giving them some good UK noise? Did you expect some Karajan or Diana Krall? Hell no! When I test speakers, I do so whith music I have listened a million times and love.

 

[Simply Stereo]

Dealer alert! Just wanted to pop in and give some feedback. We are currently waiting for our Reference 1/3/5 Meta and Blade 1 Meta demos.

As soon as we get the Reference 1's -- I'd love to send one (or both) to Amir for testing. I have opened dialogue with Amir in the past but forgot the login info I was using previously, so I will reach out to him now and see if he'd be interested.

 

[warthor]

Dealer alert! Just wanted to pop in and give some feedback. We are currently waiting for our Reference 1/3/5 Meta and Blade 1 Meta demos.

As soon as we get the Reference 1's -- I'd love to send one (or both) to Amir for testing. I have opened dialogue with Amir in the past but forgot the login info I was using previously, so I will reach out to him now and see if he'd be interested.

This will be very helpful because the current scores are based on KEF data. We can see how closely the scores align. Thanks!

 

[BrokenEnglishGuy]

Real Reference 5 meta
From Nintronics audio

 

[bo_knows]

Real Reference 5 meta
From Nintronics audio

The cables are on the floor and no lifters. Speakers not 6 feet into the room. Hmmm, I don't know about that setup. Oh, and those power cables look pretty thin in the back.