New cone materials

[djjustice]

I'm curious, what other elements out there do you think driver manufacturers could exploit to create more accurate sound? What about lithium? I know it isn't very strong, but neither are most paper cones, and its very light; it could be used for a new type of tweeter. And what about using crystallized forms of elements like sodium to create an ultra hard membrane? I fell like there not experimenting enough with new ideas to advance the technologies used in modern drivers.

[jtaylor]

> I'm curious, what other elements out there
> do you think driver manufacturers could
> exploit to create more accurate sound? What
> about lithium? I know it isn't very strong,
> but neither are most paper cones, and its
> very light; it could be used for a new type
> of tweeter. And what about using
> crystallized forms of elements like sodium
> to create an ultra hard membrane? I fell
> like there not experimenting enough with new
> ideas to advance the technologies used in
> modern drivers.

It would seem with all the great strength and ability to transfer sound waves that the use of spider web material would make for extremely accurate high frequency drivers as well as in the low frequency spectrum.I would like to see more research in that direction.

J. Taylor

[blair]

Oh great they are on to me. I better hide my nest of funnel-webs I have been harvesting my stash from.

Blair

[shawn_a]

Provided Link: Fun with Sodium (http://www.theodoregray.com/PeriodicTable/Stories/011.2/)


A sodium membrane on a cone, big sloppy dog comes in from playing in the rain and shakes it out right in front of your speakers. And away goes your speakers in a bright flash of light and smoke. Out with a bang! Woohoo!

shawn

[jonpike]

Awwww man!!! That just brings a tear to my eye... the memories...

I got to help with the, uh, safe elimination of about 1/2lb of Sodium, out on a desert lakebed...

And, I had the opportunity to throw about 1/4lb of Potassium chunks into a rival HS's swimming pool... The Alkali Metals get more reactive the farther down the table you go... ;-) Did that multiple explode, fragments land again, explode, more fragments land, explode thing......

Names? Dates? Locations?? I know nothing... and long, long, past any statutes of limitations. No animals or humans harmed during the frivolites. YMMV....

> A sodium membrane on a cone, big sloppy dog
> comes in from playing in the rain and shakes
> it out right in front of your speakers. And
> away goes your speakers in a bright flash of
> light and smoke. Out with a bang! Woohoo!

> shawn

[zach_t]

Next step will be nano-technology, composite materials made up of very thin layers of various materials. I picture "hallow" cross-sections also that reduce weight, but keep stiffness.

[shawn_a]

Have you seen this one yet?

<A HREF="http://www.youtube.com/watch?v=TBLr_XrooLs">http://www.youtube.com/watch?v=TBLr_XrooLs</A>

shawn

[mike_e]

> Next step will be nano-technology, composite
> materials made up of very thin layers of
> various materials. I picture
> "hallow" cross-sections also that
> reduce weight, but keep stiffness.
would be like a honey comb, would be interesting to see some drivers like that.

[chrish]

think about it, silk dome tweeters.

[rory]

As I mentioned in a previous thread, I think that the sound of any driver having a cone with a woven structure is highly dependent on the resin or doping compound that is applied, because gaps between the fiber bundles themselves would naturally open and close otherwise, producing other weird effects. The doping compound applied to a silk dome tweeter provides some stiffness, but also damps any relative motion between the fibers that make up the fabric dome.

[Andy_G]

> would be like a honey comb, would be
> interesting to see some drivers like that.

the old kef B139?

[mike_e]

> the old kef B139?
never saw that speaker...

[Andy_G]

> never saw that speaker...

It was an oval shaped flat speaker, made with approx 1/8" to 1/4" layer of that white foam stuff they use for packing, sandwiched between 2 aliminium foil layers..... iirc

It is still reckoned to be a very good bass driver but many. The mids....wellllll ;-))

[brianp]

. . . tend to oxidize very rapidly. Focal (and I think a few others) are making beryllium domes, which I assume are thinly coated with some kind of enamel. Or maybe the rapidly formed thin coat of oxide protects from deeper corrosion (gotta check that out). Lithium and sodium are way unstable--maybe an enamel coating would work, but they're also way soft and lacking resilience. Carbon IS used in imaginative ways--woven carbon fiber cones (ScanSpeak and others) and diamond--ie. crystallized carbon--domes (Accuton). The next heavier useful metals are magnesium and aluminum--both widely used for cones and domes. Titanium, also used because of some desirable characteristics, is much heavier than these.

I think new developments will come along in ceramics and polymers that will eventually have speaker applications, but they will be driven first by research in the military and aerospace fields, then trickle down.

> I'm curious, what other elements out there
> do you think driver manufacturers could
> exploit to create more accurate sound? What
> about lithium? I know it isn't very strong,
> but neither are most paper cones, and its
> very light; it could be used for a new type
> of tweeter. And what about using
> crystallized forms of elements like sodium
> to create an ultra hard membrane? I fell
> like there not experimenting enough with new
> ideas to advance the technologies used in
> modern drivers.

[ctbowman]

[djjustice]

Yeah, I saw that rocket fuel video. These guys make a bass driver that they claim to use a honey comb cone- <A HREF="http://sumikoaudio.net/va/prod_mahler.htm">http://sumikoaudio.net/va/prod_mahler.htm</A>.

Lithium is a metal though... my bike is a aluminum lithium alloy, and is still very strong. An alloy like that could work well, or even pure lithium for a tweeter; since I am assuming that lithium is harder/ more supportive than silk, it should work. It would just be an interesting thing to try, even if its likely that it won't work.