CNT Film 1 cm wide THN - DexMat
High price but I wonder, if this matrial would be a good idea for a ribbon
High price but I wonder, if this matrial would be a good idea for a ribbon
yea interesting stuff
At first glance I would say (at least in this form) the answer is no probably not great BUT would actually make sound for sure ha.
Aside of the numerous possible questions of durability, damping,rigidity form-ability , etc etc, there is at least one issue I see.
The resistivity to mass ratio is not even close to as good as aluminum.
You would need this CNT film to be almost 5 times thicker than aluminum film to get the same resistance in a given width strip. At that point you end up with about 3.5 times the mass of aluminum. This would be a serious reduction on sensitivity and high frequency extension .
However If you can accept a lowered sensitivity ( not sure but suspect maybe 5-8 db) then can get the HF extension back
It will work BUT there are many issues yet to be tested. Is it brittle, Will it crack at the terminations? will it buzz due to non flatness "oil can" resonances, the thickness spec is suspect ( does it vary widly within a small length, ????
At first glance I would say (at least in this form) the answer is no probably not great BUT would actually make sound for sure ha.
Aside of the numerous possible questions of durability, damping,rigidity form-ability , etc etc, there is at least one issue I see.
The resistivity to mass ratio is not even close to as good as aluminum.
You would need this CNT film to be almost 5 times thicker than aluminum film to get the same resistance in a given width strip. At that point you end up with about 3.5 times the mass of aluminum. This would be a serious reduction on sensitivity and high frequency extension .
However If you can accept a lowered sensitivity ( not sure but suspect maybe 5-8 db) then can get the HF extension back
It will work BUT there are many issues yet to be tested. Is it brittle, Will it crack at the terminations? will it buzz due to non flatness "oil can" resonances, the thickness spec is suspect ( does it vary widly within a small length, ????
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Hmm yes surprisingly tough in certain directions
the tear strength along length may be an issue with vibration over time??
Testing necessary to know ?? The bending modes across the ribbons width may start a tear??
IF the self damping of this material is usefully better than metals AND it doesnt tear, then it maybe worth buying some for test. Still some concern about varied thickness along length. If weight of diaphragm changes along length then may cause some issues ??
However...
The mass of this CNT is about 25% less than aluminum by volume, but the CNTs resistance is about 5 times more than aluminum. The lower the resistance of a ribbon diaphragm, the higher the drivers sensativity that can be achieved ( within certain limitations). Lower resistance = higher amps. if using a transformer, lower diaphragm resistance alows more turns of wire on the transformer primary. In the case of a multi trace plastic backed ribbon the lower the resistance of the conducting material , the more "turns" u can put on the diaphragm. Both end in higher sensitivity.
In another example, ther is an optimum foil thickness for max sensativity when using aluminum in a ribbon diaphragm ( talking just foil only diaphragms, no plastic backing). Its around 12 micron thick. Thicker and thinner will result in less sensitivity. Thinner and the resistance starts to lower sensitivity. Thicker and the weight starts to lower it.
Its the resistivity vs mass I see a "potential" issue but perhaps not a deal breaker.
Especially for ribbons operating above maybe 3 khz where typical ribbon sensativity starts to rise anyway and the extra resistance isnt as much of a problem.
the tear strength along length may be an issue with vibration over time??
Testing necessary to know ?? The bending modes across the ribbons width may start a tear??
IF the self damping of this material is usefully better than metals AND it doesnt tear, then it maybe worth buying some for test. Still some concern about varied thickness along length. If weight of diaphragm changes along length then may cause some issues ??
However...
The mass of this CNT is about 25% less than aluminum by volume, but the CNTs resistance is about 5 times more than aluminum. The lower the resistance of a ribbon diaphragm, the higher the drivers sensativity that can be achieved ( within certain limitations). Lower resistance = higher amps. if using a transformer, lower diaphragm resistance alows more turns of wire on the transformer primary. In the case of a multi trace plastic backed ribbon the lower the resistance of the conducting material , the more "turns" u can put on the diaphragm. Both end in higher sensitivity.
In another example, ther is an optimum foil thickness for max sensativity when using aluminum in a ribbon diaphragm ( talking just foil only diaphragms, no plastic backing). Its around 12 micron thick. Thicker and thinner will result in less sensitivity. Thinner and the resistance starts to lower sensitivity. Thicker and the weight starts to lower it.
Its the resistivity vs mass I see a "potential" issue but perhaps not a deal breaker.
Especially for ribbons operating above maybe 3 khz where typical ribbon sensativity starts to rise anyway and the extra resistance isnt as much of a problem.
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