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Attempts at Circular AMTs or Ribbons?
- Thread starter Curvature
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How about a ring radiator like the JBL 075 or all the zillions of clones.
The emit - r was a circular ribbon used in the infinity kappa and crescendo speakers during their he early 90s.. Im actually listening to infinity crescendo's 3006s as i write this .. They don't suck once eq'd......
Two short ribbons with a circular aperture. All the distortion and poor low end performance of a ribbon with none of the restricted vertical dispersion.
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The Emit was actually a planar device (Electro Magnetic Induction Tweeter) It didn't have a transformer. It might be very difficult to suspend a disc in a magnetic field.
Two short ribbons with a circular aperture. All the distortion and poor low end performance of a ribbon with none of the restricted vertical dispersion.
and i learn something new.. in my research it was widely called a "ribbon" by hobbyists on forums ...
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Curvature
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A general thought: doesn't it seem like tweeters have been refined less compared to bigger drivers?
Maybe that's an unfair comment. Improvements seem to have been incremental for all drivers, really. Not as though we've seen radically new woofer technologies. Same old ideas, but optimized and executed better.
Maybe that's an unfair comment. Improvements seem to have been incremental for all drivers, really. Not as though we've seen radically new woofer technologies. Same old ideas, but optimized and executed better.
I'd love to hear @Dennis Murphy view on this subject , especially since he uses some of the best tweeters out there ( raal)...
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I'm not sure what directivity issue is being referenced. The main problem involves woofers, not tweeters. Obviously different sizes and types of tweeters will have different radiation patterns, but that just means you pick and choose. As for distortion as it applies to ribbons, RAAL has pretty much solved that problem with their latest version of the 64-10 OEM tweeter, at least at output levels that rational people require. And the best domes and AMT's don't have any distortion issues that I'm aware of, assuming they aren't run lower than they were designed to operate.
Yes, i don't hear any distortion with even the cheap amt the emotiva b1 uses... It does have a hint of sibilance , but even that isn't bad...Edit: i know the emit - r's are 30 years old but they're not bad at all ...the biggest problems with the infinity's is a rising treble response, other than that they're decent ..
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restorer-john
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Not a bad tweeter. I have a few lying around here on some Infinity speakers I should re-roll. Have all the surrounds for woofers and mids, but can't be bothered.
Directivity is solved by wavweguides. I dont see distortion issues at least for home use. Might be different for some other use cases for example when you have to put the speaker behind an acoustical transparent screen. In that case compression drivers can be used.
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"Issues" was an imprecise word on my part. There are certain obstacles and barriers that have not been overcome yet.
Take -1dB beamwidth contours. @Maiky76 posts them if you don't like messing with the posted data. Even for loudspeakers as advanced as the Genelec Ones, that contour is chaotic at best. But what's the contribution of that initial, first arriving roughness? We don't really know. The only piece of supporting but only partially related research I can think of is Geddes' suggestion that very early reflections in rooms and the equivalent on a smaller scale in waveguides have a negative effect. How negative not clear.
Then there is distortion. Both single and multitone tests show that most drivers at similar levels have similar results.
We're far from the above being a solved problem at this point.
Take -1dB beamwidth contours. @Maiky76 posts them if you don't like messing with the posted data. Even for loudspeakers as advanced as the Genelec Ones, that contour is chaotic at best. But what's the contribution of that initial, first arriving roughness? We don't really know. The only piece of supporting but only partially related research I can think of is Geddes' suggestion that very early reflections in rooms and the equivalent on a smaller scale in waveguides have a negative effect. How negative not clear.
Then there is distortion. Both single and multitone tests show that most drivers at similar levels have similar results.
We're far from the above being a solved problem at this point.
those are the emit's in my infinity's(that i found on a sidewalk,lol) in crescendo 3006's.. the emit's are ok, not extremely "refined",but they are pretty clear,overall these speakers don't suck for 30 y.o. "vintage" .. the 3 way design makes for a pretty clear midrange, they beat out jbl studio 530's (pretty easily) in my rotation..
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