A one inch voice coil is a one inch voice coil, most of the old cone tweeters I've opened up have used much smaller diametres, 12mm to 20mm. A70mm cone with a 32mm voice coil would definitely be interesting but wouldn't the high mass of the big VC raise issues?
Bliesma gave it a try. Why 34mm instead of 25mm is a mystery
https://hificompass.com/en/reviews/bliesma-t34p-4-paper-dome-concept-tweeter
https://hificompass.com/en/reviews/bliesma-t34p-4-paper-dome-concept-tweeter
Cost. Availability. Simplest technology.
Back in the day, phenolic impregnated paper domes were the standard solution.
Very popular even today in cheaper horn drivers.
Obvious indeed.
Dies "phenolic" ring a bell?
More than simple coating, they were impregnated with it, and cooked under high pressure.
Not external coating but impregnation, which is internal.
There is free space between paper fibers.
Still so useful that I made a batch of high power paper cone tweeters, go figure.
They reach way lower than any dome, greatly simplifying cabinet design , sound way louder than any dome and are more directional, which in a live Musical Instrument or PA is a bonus.
Excellent picture Galu.
Why i invariably add a layer of puzzlekoat/ModPodge to bind them all together so they can’t rub together an casue cone self-noise. Improves DDR by removing that masking affect.
dave
Why i invariably add a layer of puzzlekoat/ModPodge to bind them all together so they can’t rub together an casue cone self-noise. Improves DDR by removing that masking affect.
dave
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@JMFahey are you using any wadding or absorbing material between the paper cone and the sheet metal of the closed back tweeter?
I've always been impressed by the little Coral 50mm tweeter that had an open back and a small plastic cup filled with polyester, but it only had a 12mm voice coil; I wonder what it would have been like with a proper sized VC to handle more than 20 watts peak. I have a whole stack of small full range drivers but not really impressed with them as tweeters and my hearing above 15k isn't much good anymore
I've always been impressed by the little Coral 50mm tweeter that had an open back and a small plastic cup filled with polyester, but it only had a 12mm voice coil; I wonder what it would have been like with a proper sized VC to handle more than 20 watts peak. I have a whole stack of small full range drivers but not really impressed with them as tweeters and my hearing above 15k isn't much good anymore
Loudspeaker cone self-noise?
Now that's a concept which is currently evading my legendary googlin' skills!
I do read that the addition of synthetic fibrillating fibres with their tree-like structure to the paper pulp can mechanically bind the paper fibres together so they won't rub together.
Images of fibrillating fibres:
A term i coined and likely mostly seen here, and likely my web-site. It probasbly has mosre names — it should.
dave
Not really but gluing some felt to inside of bell would certainly help flatness.
Not too worried about in MI cabinets where the 3 most important parameters are Loud, Louder and Loudest 😄
Well, one of paper pulp components is some kind of glue.
As usual, all sauces are secret, cone makers don't divulge them even under torture.