Wood cone speakers.

[topspeed]

TAS reports that JVC is set to release speakers with, get this...wood cone speakers. Wood? WOOD! Hey, I'll be the first to admit that I'm not an engineer but doesn't wood have properties that aren't conducive to use as a speaker? Doesn't wood shrink and swell? Doesn't wood rot? Chip? Flex? Break? Stain? Seriously, this just smacks of marketing over common sense.

Who knows, maybe I'm wrong? Any engineers wanna relay how wood could actually be beneficial?

BTW, they soak the wood in Sake to keep it from becoming brittle. No, I'm not making this up.

[This Guy]

Yeah I heard that. Vifa, a very popular and good speaker driver company actually had a wood coned speaker out for a few years. It doesn't seem to popular to speaker builders, basically because of its price. The response isn't bad, but you can get a similar, more sensitive speaker for about 50% of its cost. http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=297-370

-Joey

[Woochifer]

I've heard of speakers made out of wood pulp (and by logical extension, paper is also made from wood pulp), but not something carved out of a solid block of wood. I guess it would make sense if the wood is thin and light enough and retains enough stiffness. (If you look at balsa shavings, they're not too different from paper in how pliable and lightweight they are; and paper drivers are often reinforced with stuff like epoxy to make them stiffer) That would be an interesting experiment. Something tells me that it won't be all that different from paper drivers since I doubt that they'll use something solid enough to double as a salad bowl!

[matt39]

Hey Topspeed,

On audiokarma.org they have a thread on these speakers in which they reference a prior thread which contains a link to an article which describes the development of the wood cones. It's actually pretty interesting. The wood is soaked in sake to make it malleable enough to form into a cone. It is also resin impregnated for waterproofing and treated with a mold resistance agent. You can check out the threads on that sites Speaker section.

[matt39]

Whoops I goofed. The threads are in the General Audio Discussion section, not the Speaker section. Sorry about that.

[skeptic]

Wood is not as bad a material as it might seem. It has certain advantages over paper for a woofer. Contrary to what many people think, higher mass is not an issue with woofer cones, quite the opposite. If you want a speaker with a low resonant frequency, one way to do it is to increase the mass. Also, wood can be stronger than paper to resist bending and flexing modes which only add distortion. I'm surprised that many other manufacturers haven't tried this idea. Impregnating the wood with various substances to improve it formability into a cone, improve its rigidity, and increase its resistance to various modes of deterioration seems like a very sensible approach. The one real problem I see with wood is that being a natural product, the uniformity of it from unit to unit and within each unit must be performed by careful inspecton and selection, not by controlling a manufacturing process such as with paper, plastic, metal, or other fabricated materials. If they do their job well, they will have a fairly high reject rate compared to common alternatives.

[topspeed]

[QUOTE=skeptic The one real problem I see with wood is that being a natural product, the uniformity of it from unit to unit and within each unit must be performed by careful inspecton and selection, not by controlling a manufacturing process such as with paper, plastic, metal, or other fabricated materials. [/QUOTE]

That's a really good point, Skep.

It's hard for me to fathom why anyone would go to this much trouble unless it is technically superior to available (and cheaper) materials such as aluminum, plastic (poly impregnated whatever is still plastic), kevlar, and carbon fiber to name but a few. Maybe it has properties these others don't?

[WmAx]

It's hard for me to fathom why anyone would go to this much trouble unless it is technically superior to available (and cheaper) materials such as aluminum, plastic (poly impregnated whatever is still plastic), kevlar, and carbon fiber to name but a few. Maybe it has properties these others don't?
IT's easy for me to imagine a non-technical reason; "100% Natural wood diaphrams for the ultimate in natural sound reproduction." is just one huge MARKETING reason! :-)

As for technical superiority -- I can't think of anything that would make solid wood perform better than or even equal to some of the synthetic constructions. I'de have to see comparative measurements of adequate resolution compared to the best property alternatives to prove technical superiority.


-Chris

[skeptic]

One possibility is that treated wood may have a superior ability to dampen resonances within its own structure. I don't know, just a thought.

[WmAx]

One possibility is that treated wood may have a superior ability to dampen resonances within its own structure. I don't know, just a thought.Seems extremely doubtful. Observe a modern design such as JM Lab/Focal W cone design. Plyed layers of fiberglass with foam core contained between the layers. The results is an extraodrinarly stiff design with extremely effective thermal conversion of resonances. How about SEAS magnesium cones? While not very effective at convertinog the reonances(not exactly a 'new' material, either) to thermal energy, they are designed to push the resonant modes above the intended band the driver is to be used, thus providing a nearly perfect pistonic behaviour. I don't know what wood could provide the properties to the degree of either of these two examples. But of course; I am glad to see measurements to confirm or deny my suspicions.

Notice that the only item the wood cone speaker is used on right now is a low cost integrated mini-system? If this is a breaktrhough product in technical performance, why is it premiered in such an application? Just wondering.

Note that my perspective is that of a skeptic; this item is new/unproven and I'll have to see substantiation in order to accept as an 'improvement' over existing products.

-Chris

[mtrycraft]

One possibility is that treated wood may have a superior ability to dampen resonances within its own structure. I don't know, just a thought.


I wonder how thick that wood cone is and how much it matters after all the penetrating chemicals and sealers used on it, from the description above. It's probably wood in name only :)

[Sealed]

The VIFA "wood" cone is essentially wood pulp (paper) treated. The JVC: well, who cares, it sounds like crap. It's a gimmick more than an audio breakthrough.

Wood does have decent self damping and stiffness to mass. But there really is no such thing as pure anything in a driver.

Paper= doped paper (treated, bonded etc) good self damping and stiffness
Kevlar= polykevlar (treated or interwoven) kevlar by iteself resonates badly good stiffness
Polypropelene: yes, there was pure poly, but now it's mostly poly+ carbon fairly stiff, good damping.
WCF: A couple of companies use woven carbon fiber, very stiff, light and quiet
Aluminum/metal: poor self damping, so they are usually honeycomb or coated. metal has bad self damping. Good stiffness (rigidity) IMO, makes good bass drivers.
Fibreglass: usually polyglass
etc.

There is no "one best" and each has tradeoffs.