Cones are a bit of a controversial topic. I normally think that the ideal cone should infinitely stiff. Thus no resonances or breakups can occur. Carbon fiber Honeycomb sandwich cones are the best according to me, since they are very stiff and very light. This should improve transient response, and also push breakup frequencies very high.
Please visit my site www.moraalacoustics.com for more information on the design and development of loudspeaker drivers. You will find information on materials and manufacturing processes
Please visit my site www.moraalacoustics.com for more information on the design and development of loudspeaker drivers. You will find information on materials and manufacturing processes
Re: Interesting take
That would be ideal (at least until carbon nanotubes come onto the scene). For MPCVD diamond, the size limit about 16", but I don't know if curved profiles can be deposited.Jimmy154 said:
I think the Eton carbon fibre or kevlar not sure which and inbetween honeycomb shape has the best strength stiffness per weight, that's why I chose them. The kevlar or carbon fibre is not the issue it's the honeycomb that attracted me, although just of-the-cuff I would say carbon fiber is slightly stronger stiffer than kevlar. I haven't listened to many speakers, but I try to judge based on what seems logically to be the best material(s).
I would think wood fiber or paper cones would have the best internal damping or maybe polypropolene. I don't know though? Or aerogel, I don't even know what that is? I know which cone should be have the best stiffness to weight or the least the best strength to weight ratio (which I would imagine it not that critical unless you going to be kicking your speakers). I would imagine ceramic cones are stiffer than carbon fiber honeycomb sandwhich cone, but then carbon fiber honeycomb can be made a lot thicker than ceranics, which of course is much stiffer. Twice the thickness about 8 times the stiffness (incase you didn't know). So a lot comes into play. Wood fiber cone might sound the most natural, cause it comes from the ground man (to quote some marijuana advocates), but I can't give I rational reason, just like those marijuana advocates.
I read that article some one suggested. Go with Diamond. If your speakers don't sound good you can wear them around your neck
Diamond is stiffer than carbon fibre, but the honeycomb has air (which is very light last I checked) pockets between two surfaces. Also can be made for woofers (I'm guessing here) four times as thick as diamond for the same weight, that's about 64 times (althought it's probalby less cause of the air spaces, it's not solid all the way through) as stiff as diamond if diamond had the same stiffness. I don't know how much stiffer diamond actually is than the stiffest carbon fiber. But if it's like a factor of five or ten, than the carbon fiber honeycomb sandwhich might be stiffer for it's weight/shape. How bout a diamond honeycomb sandwhich?
His presentation would disgust a student of Argumentation 101.mashaffer said:
You lock yourself into a narrow range of solutions with this limitation. Control of stiffness is really the key- one would ideally like to make it what one wants where one wants. If you want a stiff cone or diaphragm everywhere, that's really just one option among a lot of potential solutions.
Speaker cones and diaphragms suffer amazingly from a lack of creative approaches.
Sy makes a good point re cone stiffness.
The reason behind my rant on the history of cone development was to show that despite new materials with greater stiffness, we are still no closer to reproducing sound accurately enough to deceive anybody that it is not "reproduced", and in fact paper, one of the oldest materials, is still probably the most popular. And in fact although drivers have improved a little over the last fifty years, there has been no major breakthrough, equivalent say to the transistor or the jet engine.
The Rice-Kellog design is a dead-end, with limitations that can be reduced, but not eliminated..
All cones have a range of resonances, (not to mention those due to their suspension, and the box they are in), and in addition multidriver units have a discontinuity at crossover that can be detected. We need an infinitely light, infinitely stiff, resonance free cone, which obviously we don't have.
Probably the closest we have at present in practical terms are ribbons and electrostatic, here the very light "cone" acheives stiffness by being driven over its whole surface rather than at a single point.
Plasma drivers showed promise but are impractical.
New ideas anyone?
The reason behind my rant on the history of cone development was to show that despite new materials with greater stiffness, we are still no closer to reproducing sound accurately enough to deceive anybody that it is not "reproduced", and in fact paper, one of the oldest materials, is still probably the most popular. And in fact although drivers have improved a little over the last fifty years, there has been no major breakthrough, equivalent say to the transistor or the jet engine.
The Rice-Kellog design is a dead-end, with limitations that can be reduced, but not eliminated..
All cones have a range of resonances, (not to mention those due to their suspension, and the box they are in), and in addition multidriver units have a discontinuity at crossover that can be detected. We need an infinitely light, infinitely stiff, resonance free cone, which obviously we don't have.
Probably the closest we have at present in practical terms are ribbons and electrostatic, here the very light "cone" acheives stiffness by being driven over its whole surface rather than at a single point.
Plasma drivers showed promise but are impractical.
New ideas anyone?
Re: Re: Interesting take
I'd have to disagree... when Sony released their CD white paper i just happened to be taking an advanced course on sampling theory... i was much more succinct... i said "it won't sound right until they increase the sampling rate at least 4x" I haven't seen or heard anything in the last 25 years to make me change that opinion.
Nothing on his CD page is inaccurate. (similarily a good friend. a physicist who worked on the original GPS system, dismissed CD with the simple statement "there are only 2 samples at 20k")
The inadequacy of CD is the reason why vinyl is making a resurgence and why there at least a 100 times more choices in quality TTs today than when CD was introduced -- that is people voting with their wallets despite massive pressure from the corporate entities behind CD to kill vinyl.
dave
I'd have to disagree... when Sony released their CD white paper i just happened to be taking an advanced course on sampling theory... i was much more succinct... i said "it won't sound right until they increase the sampling rate at least 4x" I haven't seen or heard anything in the last 25 years to make me change that opinion.
Nothing on his CD page is inaccurate. (similarily a good friend. a physicist who worked on the original GPS system, dismissed CD with the simple statement "there are only 2 samples at 20k")
The inadequacy of CD is the reason why vinyl is making a resurgence and why there at least a 100 times more choices in quality TTs today than when CD was introduced -- that is people voting with their wallets despite massive pressure from the corporate entities behind CD to kill vinyl.
dave
For the record I have not reached any conclusions on Altman's ideas. I think that the panels are kind of a goofy idea and some of the metaphysical stuff is a little weird but there may be something to the idea of using natural materials in loudspeakers.
I confess that I have no training in the physics of drivers but I have always had a natural skepticism about making speaker cones out of things like metal.
I specifically mentioned his site with the idea of getting some discussion of whether the natural resonances of paper might be more suited to speaker cones.
Given that any material will have resonances it seems that a material with multiple resonances spread over a wide spectrum (with no one freq. dominating) would be preferable to one with pronounced resonance in a small band (as I would expect from a rigid homogeneous material). Am I off base here?
mike
I confess that I have no training in the physics of drivers but I have always had a natural skepticism about making speaker cones out of things like metal.
I specifically mentioned his site with the idea of getting some discussion of whether the natural resonances of paper might be more suited to speaker cones.
Given that any material will have resonances it seems that a material with multiple resonances spread over a wide spectrum (with no one freq. dominating) would be preferable to one with pronounced resonance in a small band (as I would expect from a rigid homogeneous material). Am I off base here?
mike
Understandable, but such 'common sense' feelings are rarely correct. You need to think about these things logically before reaching a conclusion.mashaffer said:
He contradicts himself here. First he says that low distortion is the most important factor, then he says stiff, i.e. metal cones are no good. But stiff, metal cones give lower distortion than flexible cones!mashaffer said:
As for resonances: Stiff materials can have some pretty bad resonances, yes. This is not the whole picture though. If a cone has really bad resonances, but at frequencies well outside the passband then that's as good as no resonances at all. This can indeed be the case, compared to paper cones, which will be doing all sorts of unwanted things over a broad frequency range, including the frequencies the cone is supposed to be reproducing.
Personally I'm a fan of metal cones. I like the low distortion, which to my ears gives a very uncoloured sound. Paper is a good material of course, which is why it's so commonly used, but it's not the ideal material.
The important concept of the metal cone is to use a material that does not absorb motion driven by the coil, so when you have a metal cone, you would normally have metal coil as well.
Ideally you would want a totally rigid cone with the natural modes well damped. If you dont have a strong enough motor to drive the full mass of a cone at HF, then you would take the concept of flexible cone. I think you can see Jordans cones becomming more and more rigid throughout the generations. Guys developing drivers really should consult this man, and apply new technology, if you what to develope ultimate drivers. Of course for the DIYer, most may not afford it.
The suspension system also plays an important role.
NXT uses a different approach, but I don't know if one would call it HIFI or not.
Ideally you would want a totally rigid cone with the natural modes well damped. If you dont have a strong enough motor to drive the full mass of a cone at HF, then you would take the concept of flexible cone. I think you can see Jordans cones becomming more and more rigid throughout the generations. Guys developing drivers really should consult this man, and apply new technology, if you what to develope ultimate drivers. Of course for the DIYer, most may not afford it.
The suspension system also plays an important role.
NXT uses a different approach, but I don't know if one would call it HIFI or not.
tired old cd vs. vinyl..
>I'd have to disagree... when Sony released their CD white paper i just happened to be taking an advanced course on >sampling theory... i was much more succinct... i said "it won't sound right until they increase the sampling rate at least >4x" I haven't seen or heard anything in the last 25 years to make me change that opinion.
your loss... I'll trade noisy lossy vinyl for the limitations of digital any day... all of the negatives attributed to cd's over the last 1/4 century can be traced to clueless engineers who failed to understand the different requirements of the medium.
>Nothing on his CD page is inaccurate. (similarily a good friend. a physicist who worked on the original GPS system, >dismissed CD with the simple statement "there are only 2 samples at 20k")
... and little of it is relevant either. The "2 sample" argument is sooo tired as to be laughable. Ever look at the specturm of a 20 Khz vinyl signal trying to be reproduced through the RIAA filter/reconstructor using most any system at any kind of realistic level??? And lets not forget what happens at the low end of the spectrum, what with groove modulated dynamic compression, warp, rumble, etc. Not a pretty sight. Besides, who (other than bats) listens to any source material with a 20 KHz fundamental signal (I know, all that tripe about harmonics and such) not gonna fly.. it's been proven to be irrelevant.
>The inadequacy of CD is the reason why vinyl is making a resurgence and why there at least a 100 times more choices in >quality TTs today than when CD was introduced -- that is people voting with their wallets despite massive pressure from >the corporate entities behind CD to kill vinyl.
twice the dynamic range... 1/10th the freq. variations, orders of magnitude less distortion... yupp that's SHURE (sic) inadequate alright.
maybe up north that's true... not down south here in KY. Only folks trying to sell vinyl down here are those who think wires have different sound... reminds me of the mmtb argument...
>I'd have to disagree... when Sony released their CD white paper i just happened to be taking an advanced course on >sampling theory... i was much more succinct... i said "it won't sound right until they increase the sampling rate at least >4x" I haven't seen or heard anything in the last 25 years to make me change that opinion.
your loss... I'll trade noisy lossy vinyl for the limitations of digital any day... all of the negatives attributed to cd's over the last 1/4 century can be traced to clueless engineers who failed to understand the different requirements of the medium.
>Nothing on his CD page is inaccurate. (similarily a good friend. a physicist who worked on the original GPS system, >dismissed CD with the simple statement "there are only 2 samples at 20k")
... and little of it is relevant either. The "2 sample" argument is sooo tired as to be laughable. Ever look at the specturm of a 20 Khz vinyl signal trying to be reproduced through the RIAA filter/reconstructor using most any system at any kind of realistic level??? And lets not forget what happens at the low end of the spectrum, what with groove modulated dynamic compression, warp, rumble, etc. Not a pretty sight. Besides, who (other than bats) listens to any source material with a 20 KHz fundamental signal (I know, all that tripe about harmonics and such) not gonna fly.. it's been proven to be irrelevant.
>The inadequacy of CD is the reason why vinyl is making a resurgence and why there at least a 100 times more choices in >quality TTs today than when CD was introduced -- that is people voting with their wallets despite massive pressure from >the corporate entities behind CD to kill vinyl.
twice the dynamic range... 1/10th the freq. variations, orders of magnitude less distortion... yupp that's SHURE (sic) inadequate alright.
maybe up north that's true... not down south here in KY. Only folks trying to sell vinyl down here are those who think wires have different sound... reminds me of the mmtb argument...
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