Question. The Carver ALS I have utilize two aluminized traces in the Kapton ribbons. The current flows inside the assembly of the driver up one trace then crosses over at the top and flows down the other trace to close the circuit to the amp. (Flows up and back down inth eassembly)
What if a single layer of continuous aluminized mylar were used as the diaphram? Aluminized mylar of maybe .0005" thickness? Similar to a space blanket. Or the material used in floral shops. The current could flow into the ribbon at the bottom of the ribbon utilizing both connectors as the leads in, flow to the top out both leads, and then the circuit would be closed outside the ribbon assembly by wire from the top of the assembly
Instead of a flow up and then down within the assembly, the flow would be up and out (one way)through the asembly, and back to the amp.
Could this not work?
What if a single layer of continuous aluminized mylar were used as the diaphram? Aluminized mylar of maybe .0005" thickness? Similar to a space blanket. Or the material used in floral shops. The current could flow into the ribbon at the bottom of the ribbon utilizing both connectors as the leads in, flow to the top out both leads, and then the circuit would be closed outside the ribbon assembly by wire from the top of the assembly
Instead of a flow up and then down within the assembly, the flow would be up and out (one way)through the asembly, and back to the amp.
Could this not work?
That will result in the whole diaphragm getting shoved sideways instead of pleated sides moving towards and away from each other. I think.
Carver ribbon ... not familiar with it.
What are its dimensions ... the ribbon's dimensions.
Continuous ribbon will need magnets side to side. Ribbon has to move front and back.
Cool.
Srinath.
Carver ribbon ... not familiar with it.
What are its dimensions ... the ribbon's dimensions.
Continuous ribbon will need magnets side to side. Ribbon has to move front and back.
Cool.
Srinath.
Thanks for the reply:
The Carver "ribbon" is not a true ribbon. Kapton. Two traces of aluminum applied by vacuum depositon. The traces are .312" wide and spaced .750" appart. Ribbon is maybe 5 inches wide stretched over a 4 in frame.
The ribbon is held into the enclosure by tensioning along the entire edge. Top sides and bottom. That is to say that there is no loose edge as in a true ribbon.
It is really more like a diaphram that would be used in an electrostat except instead of the transformers and current deflecting the diaphram through a static field.... the diaphram in this case is placed in proximity to 3 strips of neo magnets. The actual traces fit between the 3 sets of magnets. And of course the current flow through the traces interacts wihtthe static mag fields imposed by the magnets and moves the diaphram.
It is a pull system not a push and pull. Magnets are on one side of the diaphram only.
I am wondering what the effect would be to run the current going only one way through the mag field instead of in up across and back down the other trace.
If you know it would help a lot. I am tired of having this repaired inadequately. If you don't know what the efect would be, or if the aluminized mylar would survive...maybe you know someone who would know?
The Carver "ribbon" is not a true ribbon. Kapton. Two traces of aluminum applied by vacuum depositon. The traces are .312" wide and spaced .750" appart. Ribbon is maybe 5 inches wide stretched over a 4 in frame.
The ribbon is held into the enclosure by tensioning along the entire edge. Top sides and bottom. That is to say that there is no loose edge as in a true ribbon.
It is really more like a diaphram that would be used in an electrostat except instead of the transformers and current deflecting the diaphram through a static field.... the diaphram in this case is placed in proximity to 3 strips of neo magnets. The actual traces fit between the 3 sets of magnets. And of course the current flow through the traces interacts wihtthe static mag fields imposed by the magnets and moves the diaphram.
It is a pull system not a push and pull. Magnets are on one side of the diaphram only.
I am wondering what the effect would be to run the current going only one way through the mag field instead of in up across and back down the other trace.
If you know it would help a lot. I am tired of having this repaired inadequately. If you don't know what the efect would be, or if the aluminized mylar would survive...maybe you know someone who would know?
That is such a cool description. Tensioning them is easy, magnets are easy. I guess I need to google up a picture. BTW I love the ribbon or other un conventional tweeters. They really really work.
Cool.
Srinath.
Cool.
Srinath.
The question then is:
Will using the entire surface of the aluminized mylar as the conductor work. Will it conduct enough current?
And what wil be the effect of running the current only one way throught the magnetic field instead of in and themn back out.
It seems to me that with the current design with two traces there is a potential for the two linear halves of the diaphram to be slightly out of phase in motion. The extreme speed of the signal through the ribbon is what negates the sonic effect of this phase shift.
So I would think that really a single continuous conductive surface of sufficient lightness and durability. Like aluminized mylar...should actually work better?
Will using the entire surface of the aluminized mylar as the conductor work. Will it conduct enough current?
And what wil be the effect of running the current only one way throught the magnetic field instead of in and themn back out.
It seems to me that with the current design with two traces there is a potential for the two linear halves of the diaphram to be slightly out of phase in motion. The extreme speed of the signal through the ribbon is what negates the sonic effect of this phase shift.
So I would think that really a single continuous conductive surface of sufficient lightness and durability. Like aluminized mylar...should actually work better?
Correction - the Carver as well as the B&G drivers are in fact push-pull. The magnets are both in front of, and behind the planar ribbon. Most of the magneplanars on the other hand are made with the magnets only in front of the planar driver. Their most expensive speaker uses both push-pull and true ribbon design.
The design mentioned here in the question above would work, However there would be problems. First, the moving mass would be greatly increased, causing lower efficiency and more then likely an early roll off on the high end. The impedance would also drop quite low, perhaps a to about 1/4 ohm? All in all, not a good idea I'd say.
The design mentioned here in the question above would work, However there would be problems. First, the moving mass would be greatly increased, causing lower efficiency and more then likely an early roll off on the high end. The impedance would also drop quite low, perhaps a to about 1/4 ohm? All in all, not a good idea I'd say.
Oh yea some of the infinity Kappa early series, maybe the 5.1 or even earlier would nearly drop to under 1 ohm. That was with EMIT and EMIM and a woofer. Can you say fry my amp please.
I suspect that lead infinity to dump the EMIM.
Cool.
Srinath.
I suspect that lead infinity to dump the EMIM.
Cool.
Srinath.
How the ribbon is made
OK this is 3 years too late and likely 1000's of $$$ short ...
But I dissected a carver AL-iii earlier this week.
This is what there is in it.
Front face and rear face plates have magnets in the repel position front to back. Assuming the plates are hung in front of you assembled in the tweeter this is how they are arranged.
In each plate on the left lets call it column 1 is something like n8 grade magnets 3/8"by 3/8" by ~6" long but they re stacked one below the other tightly, making for 1 long column of North pole facing the ribbon and barely 1-2mm from it. Column 2 ~3/8th" to the right of it is the same, but south is facing the ribbon. Column 3 is same as column 1 - north facing the ribbon.
The rear plate is the same ... north to ribbon, then south to ribbon, then north again. Else the 2 magnets will clang into each other and kill your ribbon in a matter of seconds. The front plate and reat plate are perfectly positioned to repel each other with several 10's of lbs of force.
The magnetic field in the magnet assembly is outside to inside - column 1-> column 2 and column 3 -> column 2. Presumably its very very uniform the entire height of the setup.
Then the ribbon.
There is 4 columns of conductors. 1 set of 2 facing the gap between magnet columns 1 and 2, and the other set of 2 facing the gap between magnet columns 2 and 3. So they are in ~3/8" space right next to each other. The current flows in the same direction in 1 and 2, say top to bottom, and bottom to top in conductors 3 and 4. These 2 are sitting in magnetic fields of opposite direction, so they have opposite current flows ... so when they get a signal, the entire ribbon is shoved forward ...
You can test each conductor for continuity and as I am hoping, find a way to repair one if there is a split using one of em famous metal window defroster pens.
There wasn't much glue keeping the magnets in place, which may be fine for general operation, but if you bump it in transport or trying to take it apart - you should ahve somethign keeping them apart. I plan on putting in a few plastic dowels in there as well as glue to the base.
Cool.
Srinath.
OK this is 3 years too late and likely 1000's of $$$ short ...
But I dissected a carver AL-iii earlier this week.
This is what there is in it.
Front face and rear face plates have magnets in the repel position front to back. Assuming the plates are hung in front of you assembled in the tweeter this is how they are arranged.
In each plate on the left lets call it column 1 is something like n8 grade magnets 3/8"by 3/8" by ~6" long but they re stacked one below the other tightly, making for 1 long column of North pole facing the ribbon and barely 1-2mm from it. Column 2 ~3/8th" to the right of it is the same, but south is facing the ribbon. Column 3 is same as column 1 - north facing the ribbon.
The rear plate is the same ... north to ribbon, then south to ribbon, then north again. Else the 2 magnets will clang into each other and kill your ribbon in a matter of seconds. The front plate and reat plate are perfectly positioned to repel each other with several 10's of lbs of force.
The magnetic field in the magnet assembly is outside to inside - column 1-> column 2 and column 3 -> column 2. Presumably its very very uniform the entire height of the setup.
Then the ribbon.
There is 4 columns of conductors. 1 set of 2 facing the gap between magnet columns 1 and 2, and the other set of 2 facing the gap between magnet columns 2 and 3. So they are in ~3/8" space right next to each other. The current flows in the same direction in 1 and 2, say top to bottom, and bottom to top in conductors 3 and 4. These 2 are sitting in magnetic fields of opposite direction, so they have opposite current flows ... so when they get a signal, the entire ribbon is shoved forward ...
You can test each conductor for continuity and as I am hoping, find a way to repair one if there is a split using one of em famous metal window defroster pens.
There wasn't much glue keeping the magnets in place, which may be fine for general operation, but if you bump it in transport or trying to take it apart - you should ahve somethign keeping them apart. I plan on putting in a few plastic dowels in there as well as glue to the base.
Cool.
Srinath.
OK cool, I am hoping to just use a metal trace (either a PCB repair pen or a rear window defroster pen) to get it fixed. Hopefully I find it, trace it, and glue the kapton back where it is ripped.
Cool.
Srinath.
Cool.
Srinath.
I have bought a 24" x 300' roll of aluminized mylar from a massage spa supplier - its the thermal blanket they give you for massages. It was all of $30 and I have tons left for more experiments- originally an ESL driver (somewhat successful)
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That was rather thick wasn't it. This bugger is the thinnest you can find ... This is 1 layers of kapton and 4 lines of aluminum all under 1 mil thickness ... I think.
Cool.
Srinath
Cool.
Srinath
Oooo let me look
1 sec - but this has 4 lines of aluminum in between 2 layers of kapton 1 sec ...
Cool.
Srinath.
1 sec - but this has 4 lines of aluminum in between 2 layers of kapton 1 sec ...
Cool.
Srinath.
I have kapton in it now, I think its kapton cos its heat resistant.
But I am finding .5mil ... except I have to put aluminum traces in it ... and sandwich the next .5mil on top of it.
If I find the break I'll just do that circuit writer thing and get it fixed ... I hope.
Cool.
Srinath.
But I am finding .5mil ... except I have to put aluminum traces in it ... and sandwich the next .5mil on top of it.
If I find the break I'll just do that circuit writer thing and get it fixed ... I hope.
Cool.
Srinath.
12 micron ?
12 micron - thinest I find kapton in is .5 mil, 38 microns.
I need to get that from you mylar or kapton ...
Or is it available in kapton ?
Cool.
Srinath.
12 micron - thinest I find kapton in is .5 mil, 38 microns.
I need to get that from you mylar or kapton ...
Or is it available in kapton ?
Cool.
Srinath.
Is this even right -
Material: Dupont Mylar® Type C films
Length: 40 meters
Width: 620 mm
Thickness: 2 micron
2 micron ?
I can do the ribbon in that no problem. heat or no heat ... mylar can take heat ... just not as much as kapton I guess ...
Cool.
Srinath.
Material: Dupont Mylar® Type C films
Length: 40 meters
Width: 620 mm
Thickness: 2 micron
2 micron ?
I can do the ribbon in that no problem. heat or no heat ... mylar can take heat ... just not as much as kapton I guess ...
Cool.
Srinath.
Can this work -
Metalized Mylar Tape Silver 1 2" x 216' | eBay
That is the conductor.
On to the thinnest mylar tape I can find, I just need 1 adhesive side - that will be the metalized mylar tape, I will try to find the thing in 1/8th thickness, and it will work perfect I hope ...
The conductor .9 mil I think is inevitable for that, the rest of it being super thin and light woud compensate that extra weight.
Cool.
Srinath.
Metalized Mylar Tape Silver 1 2" x 216' | eBay
That is the conductor.
On to the thinnest mylar tape I can find, I just need 1 adhesive side - that will be the metalized mylar tape, I will try to find the thing in 1/8th thickness, and it will work perfect I hope ...
The conductor .9 mil I think is inevitable for that, the rest of it being super thin and light woud compensate that extra weight.
Cool.
Srinath.
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