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  • Metamaterial Absorption Technology

    Steve Guttenburg recently posted a review of the new KEF LS 50 Meta speakers which utilize Metamaterial Absorption Technology to attenuate 99% of the driver back wave above 600 hz. Steve's review states that it is quite effective.

    Who's going to be first to 3D print some meta discs?
    Great loudspeakers disappear, leaving just the music. LS50 Meta is such a loudspeaker. The incredibly immersive sound means you lose yourself in your favourite music. Savouring every nuance as layer upon layer of instrumentation is delivered with exceptio

  • #2
    Lots of marketing speak there. What exactly are these things? How do you make them?
    Francis

    Comment


    • djg
      djg commented
      Editing a comment
      People watched that whole review? Dayum.

  • #3
    View their site. They are just a clever packaging of multiple quarter wave traps to absorb the tweeter back-wave. Not what I consider a meta-material.

    Comment


    • #4
      It looks like a grouping of Helmholtz resonators, and by the video example it only works on the back wave coming through the pole piece vent.
      www.billfitzmaurice.com
      www.billfitzmaurice.info/forum

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      • #5
        Using design concepts straight out of science fiction, KEF and AMG devised an incredible device that absorbs 99% of the unwanted energy the high-frequency driver produces.

        Oh, good heavens, spare me. I guess this kind of stuff sells speakers to uber-consumers.
        Francis

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        • #6
          This way to The Great Egress!
          www.billfitzmaurice.com
          www.billfitzmaurice.info/forum

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          • #7
            Originally posted by billfitzmaurice View Post
            This way to The Great Egress!
            It's a pity. Their stuff is OK, and I think their engineers are competent. I guess the Mickey Mouse marketing department feels they need to BS everybody. Heck, I'm a dull old engineer, maybe they do need to BS everybody
            Francis

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            • #8
              Maybe it a solution for a problem that does not exist, maybe it improves their Uni-Q driver. Before one shames the technology ( marketing BS is fair game) we should hear them.

              Comment


              • djg
                djg commented
                Editing a comment
                Like one of Paul K's TL designs.

            • #9
              Originally posted by tvrgeek View Post
              Maybe it a solution for a problem that does not exist, maybe it improves their Uni-Q driver. Before one shames the technology ( marketing BS is fair game) we should hear them.
              Problem is, whether the tech is good or not, that kind of stuff makes me wary. But as I'm quite aware, I'm not the target audience.
              Francis

              Comment


              • djg
                djg commented
                Editing a comment
                We obviously need a technology shaming thread.

            • #10
              Now Francis, No foil triangles on your doors? No wood blocks under your speaker cables? No green Sharpie on your CDs? How can you call yourself an audiophile? OH, we're engineers. My mistake.

              Well, the Q1 tweeters sure could use some improvement. I have not heard their current ones. They have gotten a bit pricy. Next summer if free to travel by then I hope, I'll head back to the Balto/DC area for British car shows and track some down to hear.

              AA or Speaker builder had a series on using staggered tubes for a bass cabinet. If I remember it worked, but was huge. Kind of like a TL. Works but is OBE.

              So I still contend, TL loading is OBE. Some seem to confuse this with saying they are not good. That's not what obsolete means. It means we can do as well or better with newer methods. Different from my argument that I have never heard a horn I could stand in my living room. I have only heard several, not all, but that includes JBL, Altec, and Klipsch. Not counting all the horrible cheap 15 inch 2-way cheap PA speakers. I would like to hear a Geedlee. The good Dr. claims to have tamed most of the problems by addressing the throat impedance, cavity resonances, inter horn resonance, vastlly better drivers, and edge diffraction.

              Another technology that works just fine but is a bit OBE is passive radiators. Maybe a small segment somewhere but I do not know of one. If your design says you need a longer port than the cabinet can withstand, maybe a better choice is a different driver than a PR. Again, not saying they don't work, just saying there is likely a better choice. We don't need to hand stuff oversize ports like Dynaco made famous any more. Worked, just not needed.

              Here is my living room. Ported Seas 7 inch. F3 around 50 Hz. Sure, I could use the space for the BUFE* to make a big TL and maybe get 2 more Hz. Wife would not be happy. Crossed over 3rd order to the 12 inch woofer in the center @ 80 Hz. Woofer F3 around 22 Hz. So my point is not that TLs don't work fine, just not needed. If I wanted a more full range 3-way rather than 2.1, I could just as easily used the space for the BUFE to house a nice 10 inch sealed and had a 25Hz F3 with low Q that blends with room gain easier without eq. 4th order just does not blend as easily with room gain. But I guess some still like that big hump in the bass. Trying to push the 7 inch lower just runs out of X-Max and distortion skyrockets, so trying to use it below 60-ish is not smart in the first place. I don't care if your 5 inch can MODEL 10 Hz lower, it's not a good choice in the real world.

              * BUFE: Our family description of the ceramic elephants brought back from V.N. by the planeloads. Big Ugly F*&^ Elephants. My wife is very fond of them.

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              • #11
                Did a TL cabinet bite you when you were a kid, or what?
                Francis

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                • #12
                  Originally posted by fpitas View Post
                  I guess the Mickey Mouse marketing department feels they need to BS everybody.
                  That's the role of all Marketing Depts...


                  Brian Steele
                  www.diysubwoofers.org

                  Comment


                  • #13
                    Originally posted by fpitas View Post
                    Did a TL cabinet bite you when you were a kid, or what?
                    In a way, yes as one of the first true hi-fi speakers I ever heard was a TL. Another was a PR. But move forward 50 years, and we have had progress.

                    Please do not confuse the definition of "obsolete" with being poor performing. Progress is doing the same or better, easier, faster, cheaper, prettier etc.


                    Rules of marketing:
                    Take your worst attribute and advertise it.
                    Examples:
                    Ford, Quality is job one
                    Curtis Mathis makes the best darn TV
                    Any ad suggesting a lite beer has any semblance of flavor.

                    Comment


                    • djg
                      djg commented
                      Editing a comment
                      British Leyland, oil leaks are good.

                  • #14
                    Makes no more or less sense to me than the 'superior sound' provided by using Japanese Spring water in the manufacture of certain woofer cones, gizmos to lift your speaker wire off the floor or "cholesterol free bananas" sold at the local greengrocer.......

                    Geoff

                    Comment


                    • #15
                      Originally posted by Geoff Millar View Post
                      Makes no more or less sense to me than the 'superior sound' provided by using Japanese Spring water in the manufacture of certain woofer cones, gizmos to lift your speaker wire off the floor or "cholesterol free bananas" sold at the local greengrocer.......

                      Geoff
                      The pity about market-speak is everything gets lost in the translation from reality. I'm willing to believe the engineers may have come up with something useful, but we may never know what it is. It also makes a sad comment on what KEF thinks about their buyers' intelligence.
                      Francis

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