Graphene - new speaker material.
Old 14th March 2013
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Graphene - new speaker material.

Old 14th March 2013
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Bose? In conjunction with some super-hero... Mighty Mouse, maybe?
Old 14th March 2013
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Bose? Maybe. But this has great potential. Some folks will be working on the speakers pretty quickly. We will know pretty soon whether it is feasible.
Old 14th March 2013
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one atom thick? sounds like it would make a great cheese knife.
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Old 14th March 2013
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I think the Neumann kh120 mkII will be using the new graphene cones - they are due out next week, I think :-)
Old 15th March 2013
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Originally Posted by jnorman View Post
I think the Neumann kh120 mkII will be using the new graphene cones - they are due out next week, I think :-)
Bad Jim strikes again.
Old 15th March 2013
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I love electrostatics and this graphene would be great there if they can excite it the way they excite gold plated Mylar. It would be thinner so transients would be really quicker. I just got a new set a year ago. If this replaces Mylar I hope my guy can retrofit what I have.
Old 15th March 2013
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There are still laws of physics which restrict the capabilities of a speaker driver, no matter the material it is made out of. Directivity is the main issue...
Old 15th March 2013
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Cone excursion another for dynamic speakers
Wouldn't mind graphene diaphragm on my Quad 63 s
Old 15th March 2013
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Originally Posted by Rolo 46 View Post
Cone excursion another for dynamic speakers
Wouldn't mind graphene diaphragm on my Quad 63 s
Roger, my thinking exactly. However, a little poking around revealed that a two inch piece is the biggest they have yet built. No doubt this will be overcome and sheets will be being made just as carbon fiber became mass produced. This could be perfect for electrostatics and other planar speakers.
Old 15th March 2013
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Originally Posted by rumleymusic View Post
one atom thick? sounds like it would make a great cheese knife.
Yes. It is a Dutch discovery.
Old 15th March 2013
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What is this material's usp ? is it the great strength before tearing or the great stiffness?
Old 16th March 2013
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Well, 300 times stronger than steel, one atom thick, a molecular structure like chicken wire. It has almost zero mass. It presents interesting possibilities for diaphragms, in speakers, microphones and headphones. It already shows great promise in reducing the cost of desalinization of sea water. There is only one layer needed to separate sea water from water. This reduces pressure used greatly which reduces required energy.

I will be interested to see what happens with it in audio.

Last edited by boojum; 16th March 2013 at 09:17 AM.. Reason: spelling
Old 16th March 2013
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I'm thinking the most likely commercial application we'll see first is "see-thru aluminum foil" or something similar...
Old 16th March 2013
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Originally Posted by joelpatterson View Post
I'm thinking the most likely commercial application we'll see first is "see-thru aluminum foil" or something similar...
It's here now: cling film wraps. ;o)
Old 16th March 2013
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Right, but stuff that was only one atom thick, you could probably get several miles of it on a single roll!
Old 19th March 2013
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Old 20th March 2013
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I wrote the fellow who builds my electostatics. He had this simple example of strength: "It has been calculated that a one-square meter of graphene "paper" (2D configuration) put into a hammock form would support a large cat but weigh less than one of its whiskers."

He also said it is doubtful now that it could replace Mylar. His Mylar sheets are already thinner than the optimum and way thicker than graphene. I will see if he will allow me to quote his in-depth note on the subject. He also said numerous customers had written him and that he had also been following graphene for some time.

Cheers
Old 20th March 2013
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Transparent aluminum has already been done.
Shucks, beat me to it. "There be Whales here!"
Old 20th March 2013
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It's never really going to catch on until it can be put in a spray can.
Old 20th March 2013
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Originally Posted by joelpatterson View Post
It's never really going to catch on until it can be put in a spray can.
Just spray those leftovers and put them into the fridge! Great idea.
Old 20th March 2013
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Dr. Roger West, co-creator of the electrostatics of SoundLabs, has consented to allow me to include his comments on graphene. It gets into some real techy talk:

"I, too, have been watching the development of graphene for use as a possible membrane in electrostatic speakers. There are still some areas that concern me.



Recently, I've had several customers inquire if I'm going to be using it on our panels. I've been aware of the material for a while but it's obvious that a marketing push is starting up, probably an exercise to find investors. it would be nice to get a piece of it to check out its properties. There appears to be a number of unique applications for the material. The question arises as to whether or not it would be beneficial for use in electrostatic speaker panels as a replacement for the current Mylar film.



Questions arise in my mind like how does graphene behave with adhesives, if its tensile strength is sufficient (no doubt but I'd like to try it anyway), what ultra-violet radiation (ie: sunlight) would do to it, how it reacts to constant corona discharge, if it fatigues with continual bending, what is its thermal expansion characteristic, is it chemically active, etc. Right up front it appears to have too low of a resistivity for use in large electrostatic speakers since the charge on the membrane of a speaker needs to have a very slow migration rate compared to the period of the lowest frequency of interest in order to function as a "fixed-charge" topology. Otherwise, the performance of the panel is adversely affected. The migration rate depends on the resistance/capacitance time constant being high enough (the resistance is that of the membrane and the capacitance is the distributed capacitance of the panel). Graphene, I surmise, has a very low resistivity which might be OK for cell phones and other devices where low frequencies are not important. Another concern is the cost of graphene. I don't think it will be cheap. Just a few years ago graphene was registered as the most expensive material on planet earth (Wikipedia). Also, can it (or will it) be fabricated into the large areas required for a large-scale speaker panel?



The extremely low mass of a film that's only one atom thick is amazing. However, there's a point with speaker design where going lower than a given mass is of no advantage. The mass of the mylar film we use is already below this point and for this reason graphene would not be of advantage. Graphene's strength is not a problem. It has been calculated that a one-square meter of graphene "paper" (2D configuration) put into a hammock form would support a large cat but weigh less than one of its whiskers.



Furthermore, a piece of Mylar that's been coated with the optimum resistivity costs a few cents per square foot. At this point in time graphene probably would cost several hundred dollars per square foot. If the cost of graphene drops to where it is competitive with Mylar and if its reaction to environmental factors is as good as Mylar and if it can be doped in a manner to provide the proper resistivity, then it might be worth considering its use as a speaker membane. Until these questions are answered I don't think it's wise to rock the boat. I feel that at this point it's premature to consider it as a suitable material for speaker membranes."
Old 25th March 2013
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And how about microphone diaphragms? It seems a hell of a lot faster than gold plated mylar. Even faster than grown nickel.
Old 25th March 2013
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I'd say your scientist friend nailed it, Sandy-- this stuff will make the hammocks of tomorrow.
Old 25th March 2013
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Or Spiderman stuff....
Old 26th March 2013
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Quote:
Originally Posted by joelpatterson View Post
I'd say your scientist friend nailed it, Sandy-- this stuff will make the hammocks of tomorrow.
well, the cat hammocks anyway
Old 26th March 2013
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for microphones nothing's faster than microphene!
Old 26th March 2013
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Quote:
Originally Posted by joeq View Post
well, the cat hammocks anyway
Dude! Think outside the hammock!
Old 27th March 2013
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Like good Dr. West explained, there is much more to a good speaker cone material than weight, strength and stiffness. Firstly, certain weight is needed depending on the frequency range, often bass cones are weighted more to lower the resonant frequency. What good would it do to have hugely expensive and practically weightless material and then have to add lead to arrive to the required acoustic result? Another thing is stiffness, many midrange drivers rely on relatively soft plastics so that the higher frequencies are killed before reaching the edge of the cone, this keeps the radiation angle constant. Having very stiff material would NOT work as well. Strength understood in the conventional matter does not really matter much, relatively weak paper is still one of the best materials for bass/midrange cones. Where lightness and stiffness is most needed is in tweeters and microphones, but even there we now reach past the audible range with the materials available right now. It is nice to have new materials, but I doubt that graphene is going to make any major impact like polypropylene did 30 years ago, or the invention of mid & high frequency domes, or waveguides.
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