I'm a bit behind on my reading--just got to the October issue of Scientific American.
On page 53, there is an article on artificial muscles, which are made by placing an electrode on each side of an elastomer sheet. Voltage across the electrodes cause the elastomer to change dimensions. Okay...so what? Well, on page 57, they show a membrane which goes from flat to dome-shaped with the application of voltage. On the next page, they offer some information specifically on applying this to loudspeaker construction. They note that mid-range and high frequency drivers have already been made, and that there is no reason why a woofer could not be constructed using the same technology. They cite the mid-range and tweeters as offering 'good performance,' although there's no way of telling whether that's in comparison to a boom box or a high end system.
A few points to note:
--There are both low and high voltage versions of this technology. In the picture, they show the membrane being actuated by a 5kV supply. Tubes, anyone?
Don't panic, Rodd, they mention lower voltages earlier in the article--in the single digit range.
--The construction is basically that of a capacitor. They don't mention any numbers as to whether we're talking pF, uF, F...
--How close drivers are to market, they do not say, but they're already trying to get some other applications out the door. It could be that we might see the first drivers in the next year or two.
--Reliability could be a problem. Or maybe not. They mention breakdown of the membranes if you exceed a given voltage, but, hey, it's not as though current technologies have infinite capability to take abuse.
Just don't be surprised when it shows up at Madisound, Parts Express, et. al.
Grey
On page 53, there is an article on artificial muscles, which are made by placing an electrode on each side of an elastomer sheet. Voltage across the electrodes cause the elastomer to change dimensions. Okay...so what? Well, on page 57, they show a membrane which goes from flat to dome-shaped with the application of voltage. On the next page, they offer some information specifically on applying this to loudspeaker construction. They note that mid-range and high frequency drivers have already been made, and that there is no reason why a woofer could not be constructed using the same technology. They cite the mid-range and tweeters as offering 'good performance,' although there's no way of telling whether that's in comparison to a boom box or a high end system.
A few points to note:
--There are both low and high voltage versions of this technology. In the picture, they show the membrane being actuated by a 5kV supply. Tubes, anyone?
Don't panic, Rodd, they mention lower voltages earlier in the article--in the single digit range.
--The construction is basically that of a capacitor. They don't mention any numbers as to whether we're talking pF, uF, F...
--How close drivers are to market, they do not say, but they're already trying to get some other applications out the door. It could be that we might see the first drivers in the next year or two.
--Reliability could be a problem. Or maybe not. They mention breakdown of the membranes if you exceed a given voltage, but, hey, it's not as though current technologies have infinite capability to take abuse.
Just don't be surprised when it shows up at Madisound, Parts Express, et. al.
Grey
Grey:
Sounds great, although it seems remarkably similar to piezoelectric film. I bought one of those samples years ago, and got very little sound out of a 3in by 5in sheet-even the high frequency sound was not coming through with much volume.
Let's see how this one pans out. I'd like to see things move forward, especially in the direction of square diaphragms.
Personally, I think someone who wants to tool up and make 1" and 2" electrostatic squares with rigid, resonance-free electrodes, ready to add in line source arrays or in large rectangular arrangements, might find himself with a lot of customers.
But maybe this new material is the way to go.
PS: Grey, great to see you back on the Loudspeaker forum!
Sounds great, although it seems remarkably similar to piezoelectric film. I bought one of those samples years ago, and got very little sound out of a 3in by 5in sheet-even the high frequency sound was not coming through with much volume.
Let's see how this one pans out. I'd like to see things move forward, especially in the direction of square diaphragms.
Personally, I think someone who wants to tool up and make 1" and 2" electrostatic squares with rigid, resonance-free electrodes, ready to add in line source arrays or in large rectangular arrangements, might find himself with a lot of customers.
But maybe this new material is the way to go.
PS: Grey, great to see you back on the Loudspeaker forum!
Hi Grey
How are you?
This seems pretty interesting.
How does this differ from the manger??
Pardon me for not doing my homework and appropriate searching, etc.
I'm working a lot right now, at least it seems like a lot to me _big grin_ and just popped in for a look.
good to see you here.
Regards
Ken L
How are you?
This seems pretty interesting.
How does this differ from the manger??
Pardon me for not doing my homework and appropriate searching, etc.
I'm working a lot right now, at least it seems like a lot to me _big grin_ and just popped in for a look.
good to see you here.
Regards
Ken L
kelticwizard,
And a really, really good friend will move her body for you. Ahem...
They do some comparisons with piezo stuff. I've moved on to the November issue, so I don't have the article at hand at the moment. The impression I got was that there were orders of magnitude difference in the movement you could get, i.e. the elastomer critters would be more efficient. The picture shows a circular membrane an inch to two inches in diameter with perhaps a quarter-inch (maybe more) displacement. Not the kind of thing I've ever seen piezos do. Care to imagine the excursion you could get from a woofer panel? And no pesky electrostat/magnetic planar screens to get in the way, either...just the membrane itself.
Being synthetic materials, you could make any size and shape driver you wanted, I imagine.
Perhaps I ought to revamp my old Magneplanars with this stuff. On the other hand, eighteen inches of displacement might be a little intimidating!
Ken,
(Got a step-kid up there at Clemson.)
Manger...dunno. I read up on them at one point, but the particulars escape me at the moment, so I can't contrast and compare. If I get time, I'll try to scrounge around and refresh my memory on the Manger. Isn't the Manger a rigid piston that depends on breakup for higher freqencies? This thing's flexible. That'd be one difference.
Given that the October issue is almost certainly off the stands, you'd probably have to find it at a library, unless you happen to have a subscription and happened to miss the article. Pretty cool stuff, though.
Grey
And a really, really good friend will move her body for you. Ahem...
They do some comparisons with piezo stuff. I've moved on to the November issue, so I don't have the article at hand at the moment. The impression I got was that there were orders of magnitude difference in the movement you could get, i.e. the elastomer critters would be more efficient. The picture shows a circular membrane an inch to two inches in diameter with perhaps a quarter-inch (maybe more) displacement. Not the kind of thing I've ever seen piezos do. Care to imagine the excursion you could get from a woofer panel? And no pesky electrostat/magnetic planar screens to get in the way, either...just the membrane itself.
Being synthetic materials, you could make any size and shape driver you wanted, I imagine.
Perhaps I ought to revamp my old Magneplanars with this stuff. On the other hand, eighteen inches of displacement might be a little intimidating!
Ken,
(Got a step-kid up there at Clemson.)
Manger...dunno. I read up on them at one point, but the particulars escape me at the moment, so I can't contrast and compare. If I get time, I'll try to scrounge around and refresh my memory on the Manger. Isn't the Manger a rigid piston that depends on breakup for higher freqencies? This thing's flexible. That'd be one difference.
Given that the October issue is almost certainly off the stands, you'd probably have to find it at a library, unless you happen to have a subscription and happened to miss the article. Pretty cool stuff, though.
Grey
http://www.e-speakers.com/products/manger.htm
according to the literature, a flexible membrane, etc. seemed reminiscent of the principle.
I'm too tired to think it thru well.
yep, clemson's not that far up the road.
speaking of kids, I dropped by my son's house and was telling him what all I had on my plate at the moment, and so he tells me real serious like " that's gonna be good for you".
Kids! (your own, I mean) _big grin_
Actually, I think he's probably right. Semi-retirement and I didn't seem to be working out real well, in more than one way.
another glimpse of the future, hopefully will revolutionize audio in our lifetimes at this link on bucky tubes - fascinating read if you haven't read about them.
http://www.azom.com/details.asp?ArticleID=1293
regards
Ken L
according to the literature, a flexible membrane, etc. seemed reminiscent of the principle.
I'm too tired to think it thru well.
yep, clemson's not that far up the road.
speaking of kids, I dropped by my son's house and was telling him what all I had on my plate at the moment, and so he tells me real serious like " that's gonna be good for you".
Kids! (your own, I mean) _big grin_
Actually, I think he's probably right. Semi-retirement and I didn't seem to be working out real well, in more than one way.
another glimpse of the future, hopefully will revolutionize audio in our lifetimes at this link on bucky tubes - fascinating read if you haven't read about them.
http://www.azom.com/details.asp?ArticleID=1293
regards
Ken L
One driver that is made of a piezoelctric polymer is a tweeter by Audax that got good reviews. It uses an "air cored" step up x-former.
Unfortunately it isn' t made anymore but there may be some stocks left.
There were also speakers made by Pioneer in the seventies using piezo polymer tweeters.
Regards
Charles
Unfortunately it isn' t made anymore but there may be some stocks left.
There were also speakers made by Pioneer in the seventies using piezo polymer tweeters.
Regards
Charles
Re: Really Interesting!
Perhaps a better way of putting this might be...
Current technology now is rather mature, and that innovations are more likely to come from newer technologies that are still in their infancy, and may be a long time coming.
Twenty years ago, no one had ever heard of a digitial amp much less a digital crossover and now they are available as consumer items at consumer prices. Wtih growing pains to be sure, but still they have a certain amount of market penetration at a consumer level.
Such things as the speaker technologies that Grey is posting about, the Bucky tubes nanotechnology, these and other new technologies hold a lot of promise.
What am I saying??? I'm a died in the wool tube guy!!
regards
Ken L
panzk said:
Perhaps a better way of putting this might be...
Current technology now is rather mature, and that innovations are more likely to come from newer technologies that are still in their infancy, and may be a long time coming.
Twenty years ago, no one had ever heard of a digitial amp much less a digital crossover and now they are available as consumer items at consumer prices. Wtih growing pains to be sure, but still they have a certain amount of market penetration at a consumer level.
Such things as the speaker technologies that Grey is posting about, the Bucky tubes nanotechnology, these and other new technologies hold a lot of promise.
What am I saying??? I'm a died in the wool tube guy!!
regards
Ken L
Ken,
Tube guys are allowed to admire new speaker technologies. It's in the fine print on the contract. It's the solid state things that you're supposed to regard with a hostile eye. On the other hand, I wouldn't mind if someone came out with a 6550 that never had to be replaced.
It's odd to me to see someone call today's technology 'rather perfect,' as just the other day I was griping and moaning about the limitations of that same technology. We've got decent French fries, ball bearings, and toilet paper, but audio electronics...I dunno as I'd agree with that one.
Grey
Tube guys are allowed to admire new speaker technologies. It's in the fine print on the contract. It's the solid state things that you're supposed to regard with a hostile eye. On the other hand, I wouldn't mind if someone came out with a 6550 that never had to be replaced.
It's odd to me to see someone call today's technology 'rather perfect,' as just the other day I was griping and moaning about the limitations of that same technology. We've got decent French fries, ball bearings, and toilet paper, but audio electronics...I dunno as I'd agree with that one.
Grey
Our present speaker technology is hardly perfect. It's been worked on to take out some of the more egregious problems, but it really has it's limitations.
A) Cone loudpseakers only fire forward. Limited dispersion in the horizontal plane.
B) Cone speakers are round. You can't stack them one on top of the other without interference problems. If you could make them square, a long, narrow horizontal line could make up for the fact that cone speakers only fire forward.
C) Phase changes throughout the cone speaker's range. The fundamental of one note is out of phase with it's overtones.
D) Lastly, for practical purposes, the home loudspeaker only converts about 1% of the electrical energy it is fed into sound energy. More efficient cones exist, and horns are far more efficient, but for practical purposes in the home, you are operating at less than 1% efficiency.
The good part about cones is that they still can give you a great sound in a comparatively small space. Think of all the enjoyment we have, at what could be reasonable cost, compared to our own ancestors of just three generations ago. Cone loudspeakers are a big part of that-where would we be without them?
But there is definitely a lot of room for improvement.
A) Cone loudpseakers only fire forward. Limited dispersion in the horizontal plane.
B) Cone speakers are round. You can't stack them one on top of the other without interference problems. If you could make them square, a long, narrow horizontal line could make up for the fact that cone speakers only fire forward.
C) Phase changes throughout the cone speaker's range. The fundamental of one note is out of phase with it's overtones.
D) Lastly, for practical purposes, the home loudspeaker only converts about 1% of the electrical energy it is fed into sound energy. More efficient cones exist, and horns are far more efficient, but for practical purposes in the home, you are operating at less than 1% efficiency.
The good part about cones is that they still can give you a great sound in a comparatively small space. Think of all the enjoyment we have, at what could be reasonable cost, compared to our own ancestors of just three generations ago. Cone loudspeakers are a big part of that-where would we be without them?
But there is definitely a lot of room for improvement.
I know this is a bit of a stretch in terms of imagination, but bear with me.
Cavemen had it better than we do as far as music goes. Why? Because if they wanted music, they made it then and there. (Ur-DIY, so to speak.) No reproduction, no distortion, no imaging problems. Just the pure essence of music. Okay, now maybe their idea of music wouldn't match my ideals, but it was what they liked.
Nowadays, even if you play an instrument you can't necessarily always get the band together just for a tune or two, then send them home. Those who don't play don't even have that option. Reproduced music just doesn't have the same pizzazz, no matter how you slice it.
Sometimes you have to wonder if the cavemen had a favored chamber in the cave. One that sounded better than the others. Think I'm crazy? How many people do you know sing in the shower? And why do you reckon they do that? Could it be some primordial response to the sound of live human voices in an acoustically hard environment? There are all sorts of things coded into our minds that we don't think about on a day-to-day basis.
Reverberant sound like that could be why some prefer resonant speaker enclosures.
Just a thought.
Grey
Cavemen had it better than we do as far as music goes. Why? Because if they wanted music, they made it then and there. (Ur-DIY, so to speak.) No reproduction, no distortion, no imaging problems. Just the pure essence of music. Okay, now maybe their idea of music wouldn't match my ideals, but it was what they liked.
Nowadays, even if you play an instrument you can't necessarily always get the band together just for a tune or two, then send them home. Those who don't play don't even have that option. Reproduced music just doesn't have the same pizzazz, no matter how you slice it.
Sometimes you have to wonder if the cavemen had a favored chamber in the cave. One that sounded better than the others. Think I'm crazy? How many people do you know sing in the shower? And why do you reckon they do that? Could it be some primordial response to the sound of live human voices in an acoustically hard environment? There are all sorts of things coded into our minds that we don't think about on a day-to-day basis.
Reverberant sound like that could be why some prefer resonant speaker enclosures.
Just a thought.
Grey
This isn't a piezo effect, which is very strictly defined in the textbooks as being a rigid substance that flexes under the application of electricity. I believe they gave the name of the effect this is based on, but I don't remember what they called it. The elastomers they're using--e.g. silicone--are far from rigid. Think of one of those squishy pads designed to help with carpal tunnel syndrome at a computer keyboard. Actually, they named some pretty common materials that exhibit the effect, though they have gone on to find compounds that are more efficient.
Rather than depend on my description of the effect, go read the article. Perhaps the differences will be clearer then.
Grey
Rather than depend on my description of the effect, go read the article. Perhaps the differences will be clearer then.
Grey
I dropped by the library to get the article, since it is no longer on the newstands. I Xeroxed the article at the library, though I have not fully read it.
I will be scanning the article either tonight or tomorrow, and will be glad to Email it to whoever wants it. Because the library Xerox machine is black and white, the color graphics will be in black and white. But I don't think that means much.
I send scanned articles .gif, and each page is about 200Kb. When printed, this will yield a perfectly readable page. I don't mess with OCR software. If you want to deal with OCR on your end, go ahead. I don't. The scan-and-send process is much easier without it, I feel, and results in more scanned articles being sent.
For a 7 or 8 page article, that comes to well over 1 MB. Make sure your email box has enough room. If it does not, I can send the pages a couple at a time.
I will check back when the article is scanned and ready to go.
I will be scanning the article either tonight or tomorrow, and will be glad to Email it to whoever wants it. Because the library Xerox machine is black and white, the color graphics will be in black and white. But I don't think that means much.
I send scanned articles .gif, and each page is about 200Kb. When printed, this will yield a perfectly readable page. I don't mess with OCR software. If you want to deal with OCR on your end, go ahead. I don't. The scan-and-send process is much easier without it, I feel, and results in more scanned articles being sent.
For a 7 or 8 page article, that comes to well over 1 MB. Make sure your email box has enough room. If it does not, I can send the pages a couple at a time.
I will check back when the article is scanned and ready to go.
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.