That Klangfilm you picture is a super interesting prewar speaker, called the Europa Junior. The HF driver is a ribbon! The LF cone is armature driven. There is a magnetic rod that passes through the magnet and that is connected to the apex of the cone. It is a really different sounding, amazing speaker.
The model I hear in the Silbatone collection actually has two HF drivers and a forked horn (Europa a.k.a Europa Klarton). I have pics of the mechanism if i can find them. I assume that the Junior has the same driver technology as the Klarton, but I don't know this for sure.
These were sometimes installed with a large W horn in front of the woofer for some good LF coupling to the room. Never heard that setup but I suspect it is a mighty sound.
Klangfilm gear is good stuff. Seldom, if ever, heard on this continent. I am lost in the German gear world beyond a few famous items I know fairly well. There's a lot of weird old German theater and pro gear out there.
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On Beryllium, the context is this...All compression drivers have a mass rolloff due to the mass of the diaphragm. An Altec 288 or predecessor WE 594A are typical for large format aluminum. 6dB/oct rolloff from ~6kc.
Notably, this is the typical response of constant directionality horns, which do not supply the on-axis EQ of exponentials. You get the raw driver response, basically, across a large solid angle.
Drivers that go way higher are employing tricks. Yes, a lighter diaphragm might move faster and have a somewhat higher knee, but I don't think they will go much higher even if super light.
What a lot of dome tweeters and I suspect Be compression drivers do is ring like a mofo above the typical range, which looks like a desired signal on a meter but is it in time with and correlated with the input signal? Questionable.
My Beryllium experience is limited to TAD 2001s and 4004s. I wanted to like them. Couldn't stand them. They fried my brain. Felt bored and detached listening to these dogs. Went back to Altec.
The antique Klangfilm Europa might only go to 8 or 9k max, but it sounds natural. Most classic theater drivers will reach 11-13k EQed or on the right beamy horn and that is all I need for satisfying and realistic listening. i mean realistic in terms of having a tonal balance and presentation reminiscent of actual live music.
I usually hear 4-8 concerts a month, all genres, and I am just not getting the assertive detail and HF energy many audio nerds valorize when sitting in the Kennedy Center, acoustic, amplified, large or small rooms, jazz, vocals, symphony orchestra, whatever. Violins can do HF tricks that i don't think most speakers can simulate but on the whole audio has way more highs than live. Not always good highs either.
I am hesitant to spend Beryllium money only to end up with more fancy junk that is too hifi to enjoy. Maybe the new generation of diaphragms are beyond this, but I seriously doubt it. I'd give them a listen if the opportunity presents itself, but I'm not chasing more detail and tizz than I am hearing right now with 802s and EH500s.
Yeah, I'm 58 and can only solidly hear maybe 12k at the concert, but I am still 58 when listening to speakers, and the balance is too often radically-off in the HF direction. this greatly effects the way IO relate to the music. Live, I listen hard into the music, working at it. Often, hifi is like getting sprayed with a music hose. If it's gonna be leaning that that way, I prefer not using the pinpoint hose nozzle.
