Which means less motor force for a given magnetic field strength.
Keeping a uniform magnetic field will also be challenging compared to the usual circular poles
Basically I cannot see any significant difference between a round VC and an elliptical one. Best case there will be a small difference in the cone edge breakup mode owing to the different distances from the VC to the edge, but this is not necessarily better, just different.
Some years back I experimented with a random pleating in the spider and this was advantageous, but going from round to ellipse is not really random. A random pleating in the cone would also be a good idea - breakup the natural modes into random less pronounced modes, but nobody does that because of cost implications.
Some years back I experimented with a random pleating in the spider and this was advantageous, but going from round to ellipse is not really random. A random pleating in the cone would also be a good idea - breakup the natural modes into random less pronounced modes, but nobody does that because of cost implications.
Audax made an oval, gold dome tweeter in the nineties. I probably still have the specifications around somewhere in an old Madisound catalog. It was sorta weird. If I remember correctly, it had a piezo electric element driving the dome, and it was very expensive!
Dan
A piezo membrane with gas filling. A beautiful tweeter, but a fatal flaw -it leaked after a while.
HiFi World loved this unit in their top kits
That was the Audax HD-3P: https://cdn.shopify.com/s/files/1/0809/2387/files/Audax_HD_3P.pdf?17633273825937210375
As davidsrsb correctly describes:
"The HD-3P is fundamentally a piezo tweeter, it featured a gold spattered elliptical diaphragm formed onto a nitrogen filled balloon. Technically/sonically brilliant but fatally flawed due to gas loss and barometric pressure changes, many are now defunct with low or no output."
It is often nice to see different and possibly innovative things being tried. Some of the links earlier in the thread suggest some small differences, maybe this is a small step on a new path. But for now, probably much relates to sales and marketing; audiophiles crave such things to believe in and both they and consequently many hifi speaker manufacturers expect expensive drivers to look special. If it adds to the buyers sense of satisfaction then maybe it is valid, whether there is a significant audible improvement or not.
The extra cost would be unattractive to me, for such little objective benefit. But some people don't need to consider that, and/or persist in believing that more expensive must mean better and much more expensive must mean much better. Hopefully scanspeak won't use corrosive adhesive on the conductors..
The extra cost would be unattractive to me, for such little objective benefit. But some people don't need to consider that, and/or persist in believing that more expensive must mean better and much more expensive must mean much better. Hopefully scanspeak won't use corrosive adhesive on the conductors..
I took apart a blown conical 15” loudspeaker once and the voice coil was wire wrapped around a dowel. Like an electromagnet or servo.
Yeah that's the one! Looks very cool. I wonder how distortion is?
Any details of how it works inside? I can't quite imagine how a piezo element needs any gas. Any diagrams or cut away images?
The price is for each actually, 2500+
Tvey were originally advertised at around 3200, so one gets a 1400$ "discount"
Just madisound has a min. Order quantity of two, for 5000$+
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The Audax HD-3P's diaphragm consists of a pressurised piezo polymer.
Basically, the signal flows directly through the polymer diaphragm which pulsates in sympathy - no magnetic field is involved.
The resistance of the diaphragm is so low that, like a ribbon tweeter, a transformer is required to provide a normal 4/8 ohm load for the amplifier.
A full description follows:
http://www.troelsgravesen.dk/Ellipticor-84.htm
Depends on your definition of ‘gimmick’. From what I can tell, there’s not a proportional performance gain over round VC’s but in this hobby, diminished returns are often lathered up with fragrance and pomp.
Depends on your definition of ‘gimmick’. From what I can tell, there’s not a proportional performance gain over round VC’s but in this hobby, diminished returns are often lathered up with fragrance and pomp.
@DCE1198 Allow me to alter my description of how the Audax HD-3P works (post #34). My two introductory sentences should read:
Basically, the alternating voltage signal is applied directly across the piezo polymer diaphragm which pulsates in sympathy - no magnetic field is involved.
The resistance of the diaphragm is infinite and a transformer is required to provide a normal 4/8 ohm load for the amplifier.
Basically, the alternating voltage signal is applied directly across the piezo polymer diaphragm which pulsates in sympathy - no magnetic field is involved.
The resistance of the diaphragm is infinite and a transformer is required to provide a normal 4/8 ohm load for the amplifier.
It was a very interesting design. Had really good performance in its passband. I ended up going with a Raven tweeter for the project.
Dan
That is the results of they're laser vibrometer readings of midwoofer cone with round vs elliptical voice coil.
One can see different radial 'modes'. Does not mean there is not resonances or breakup.
A slightly different approach.
B&W have spent a lot of time playing with the effects of directional fibers and combinations and Anisotropic weaves, to remove the traditional cone modes in they're FST midranges.
The effect of modifying the suspension as supposed by Geddes above, and the surroudn tech of Purifi and similar is probably a bigger step in the right direction.
One can see different radial 'modes'. Does not mean there is not resonances or breakup.
A slightly different approach.
B&W have spent a lot of time playing with the effects of directional fibers and combinations and Anisotropic weaves, to remove the traditional cone modes in they're FST midranges.
The effect of modifying the suspension as supposed by Geddes above, and the surroudn tech of Purifi and similar is probably a bigger step in the right direction.
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So those 6x9 Jensen’s were low distortion? They sounded good blasting Free Bird out of a 442!