Kevlar for Speaker Cone

[coopmv]

Besides being used in the manufacturing of bullet-proof vests, Kevlar has also been used in the manufacturing of speaker cones. Do any forum members have speakers with Kevlar fibers in the woofers and do they really produce tighter bass?

http://en.wikipedia.org/wiki/Kevlar

[Cornholio]

This is hardly new, it's been used in driver cones for a couple decades. My B&W's have midrange drivers with Kevlar cones. I can't remember but I think mine were built in 1995 or 1996.

[coopmv]

This is hardly new, it's been used in driver cones for a couple decades. My B&W's have midrange drivers with Kevlar cones. I can't remember but I think mine were built in 1995 or 1996.

I am aware of the use of Kevlar in the manufacturing of speaker cones is not exactly new. It is not clear if the adoption has been universal among the speaker companies.

[Cornholio]

It is not clear if the adoption has been universal among the speaker companies.
Just look at the cones and you'll have your answer, right? I haven't looked at all the speakers ever built but it's pretty obvious only a small percentage have cones made with Kevlar. I'm confused why you're even asking this. :confused:

[coopmv]

Just look at the cones and you'll have your answer, right? I haven't looked at all the speakers ever built but it's pretty obvious only a small percentage have cones made with Kevlar. I'm confused why you're even asking this. :confused:

I am more curious as to why its adoption has not been more universal ... Is it because of cost? There certainly are many high priced speakers out there besides B&W.

[Cornholio]

I am more curious as to why its adoption has not been more universal ... Is it because of cost? There certainly are many high priced speakers out there besides B&W.
You should have just asked instead of beating around the bush. It's probably a lot of factors including cost, design, etc. There's no one right way to do things and everybody has their own way of doing things, including designers and engineers.

[Dennis Metz]

Just marketing.

[JBStephens]

Besides being used in the manufacturing of bullet-proof vests, Kevlar has also been used in the manufacturing of speaker cones. Do any forum members have speakers with Kevlar fibers in the woofers and do they really produce tighter bass?

http://en.wikipedia.org/wiki/Kevlar

"Tight" bass, "loose" bass, "fast" bass, "slow" bass, and so on are primarily functions of cabinet design and motor structure, regardless of what material the woofer cone is made from. Exotic cone materials become more relevant, though, as you approach midrange frequencies.

[nelamvr6]

I think that at least in the case of the B&W's, it FAR from just marketing.

B&W's could use whatever material they choose, they have enough clout that they would be able to sell cones made of just about anything.

They choose kevlar for good reasons.

[Dennis Metz]

I think that at least in the case of the B&W's, it FAR from just marketing.

B&W's could use whatever material they choose, they have enough clout that they would be able to sell cones made of just about anything.

They choose kevlar for good reasons.

Marketing

[nelamvr6]

"Tight" bass, "loose" bass, "fast" bass, "slow" bass, and so on are primarily functions of cabinet design and motor structure, regardless of what material the woofer cone is made from. Exotic cone materials become more relevant, though, as you approach midrange frequencies.

I'm not sure I can agree that cabinets are more important than cones, or vice versa. The entire speaker system has to work as a whole.

Good bass has come from big cabinets and small, with exotic cone material and mundane.

[Drew]

I saw a speaker kit a few years back suggested applying damar varnish to the paper cone of the mids and woofers as a tweak. Until I hear a speaker with the cone made out of kevlar or treated with damar varnish, who am I to claim superior knowledge?

[nelamvr6]

Marketing

Well it's certainly hard to find fault with your argument, especially since you have none.

Would you care to try to justify that? Or do you realize, as you should, that it would be impossible to justify such a stand?

Or are we just making statements without concerning ourselves with justification?

Let me try: B&W makes some of the finest loudspeakers in the history of humanity.

Hey, that felt good! Of course, my statement wasn't quite as silly as yours ...

[coopmv]

But my understanding is even the current production of the Klipschorns, LaScalas, Heresey, etc continue to use paper cones for their woofers, just as they did when they were first introduced almost 50 years ago. We all know these Klipsch Heritage Line speakers are quite legendary.

[Cornholio]

But my understanding is even the current production of the Klipschorns, LaScalas, Heresey, etc continue to use paper cones for their woofers, just as they did when they were first introduced almost 50 years ago. We all know these Klipsch Heritage Line speakers are quite legendary.
And that exactly what to do with Kevlar? :confused:

[nelamvr6]

But my understanding is even the current production of the Klipschorns, LaScalas, Heresey, etc continue to use paper cones for their woofers, just as they did when they were first introduced almost 50 years ago. We all know these Klipsch Heritage Line speakers are quite legendary.

I'm pretty sure that good designers can use whatever material they choose. Different materials have different strengths and weaknesses, a designer takes everything into account when choosing cone material.

According to the B&W literature, the kevlar material had strengths that they were able to exploit. That doesn't mean that kevlar is the be all and end all.

I can speak from experience, the FST Midrange drivers in the 800 series B&W speakers sounds magnificent! But I'm sure that the B&W guys could have used a different material and their speakers would still sound great, because they would keep working until they did. But they chose kevlar. You can read more about why here (http://www.bowers-wilkins.com/display.aspx?terid=1227&infid=1154&artid=1417).

[coopmv]

I'm pretty sure that good designers can use whatever material they choose. Different materials have different strengths and weaknesses, a designer takes everything into account when choosing cone material.

According to the B&W literature, the kevlar material had strengths that they were able to exploit. That doesn't mean that kevlar is the be all and end all.

I can speak from experience, the FST Midrange drivers in the 800 series B&W speakers sounds magnificent! But I'm sure that the B&W guys could have used a different material and their speakers would still sound great, because they would keep working until they did. But they chose kevlar. You can read more about why here (http://www.bowers-wilkins.com/display.aspx?terid=1227&infid=1154&artid=1417).

Nat, Thanks for that great B&W link.

[Doug Sclar]

Just got a flier from one of my distributors selling Profecient in wall speakers with Kevlar cones. They're fairly inexpensive compared to B&W.

[nelamvr6]

No, he's stuck on Kevlar and keeps bringing it up and comparing things to it and I'm trying to figure out why. My 802's have Kevlar midranges and I couldn't care less. Doesn't make a bit of difference to me if they were made out of cardboard as long as they do the job.

I'm envious! I wish I could afford 802's!

But then again, I don't think they would sound too good in my little apartment.

Weren't you the least bit curious when you first got your 802's? Did you have speakers before that used kevlar?

It is a bit unusual, so I can understand why coopmv is curious. Maybe now that he has that B&W link his curiosity will be satisfied.

[Kayaker]

My Von Schweikert 4.5's have Kevlar. If it's all marketing, then I'm willingly fooled because they sound amazing....

[jeff mai]

Very rigid materials (like kevlar) generally have severe cone break-up modes. They are not easy for designers to use to good effect because of this. The break-up modes are kind of a two-edge sword - they can create a strong sense of detail or they can cause severe colouration. It's all in the design.

[nelamvr6]

Very rigid materials (like kevlar) generally have severe cone break-up modes. They are not easy for designers to use to good effect because of this. The break-up modes are kind of a two-edge sword - they can create a strong sense of detail or they can cause severe colouration. It's all in the design.


You should check out the B&W link I posted a couple of posts ago. The B&W engineers were able to exploit the break-up modes of kevlar to good effect.

[jeff mai]

I have no doubt B&W put a lot of effort into their designs. That said, the little I've heard of the brand's sound is not to my liking. Neither are a few other kevlar drivers I've heard.

[Black Elk]

Besides being used in the manufacturing of bullet-proof vests, Kevlar has also been used in the manufacturing of speaker cones. Do any forum members have speakers with Kevlar fibers in the woofers and do they really produce tighter bass?

Like several here, I use B&W speakers (802s in my case), so have Kevlar drivers, but mid-range units rather than woofers. Do I sense it does something magical? Hard to say, as I have not heard the speaker with any other kind of driver, and B&W designed it as a system: one that works very well, IMO.

Why use it? Because designers have to find practical solutions to ideal models. Based on B&W's laser interferometry measurements of various cone materials, they came to the conclusion that Kevlar was best for mid-range drivers, Rohacell (a carbon fibre composite) for woofers and diamond for tweeters. However, these materials combine with other factors in the design to make a successful speaker. Another designer may choose to use polypropelene, paper, aluminium, mylar, etc. if that material produces the correct result within a particular design. Since there is no ideal way to design a speaker system, there is no single solution as far as driver materials, hence the reason only some manufacturers use Kevlar (overlooking any issues as to how difficult/expensive it may be to work with it).

[Cornholio]

I'm envious! I wish I could afford 802's!

But then again, I don't think they would sound too good in my little apartment.

Weren't you the least bit curious when you first got your 802's? Did you have speakers before that used kevlar?
Mine are the older Matrix series 3's and I bought them used so they weren't that expensive. I bought them because they were almost $1000 less than what they were going for on eBay, Audiogon and other places at the time so I couldn't pass them up. I was just going to keep them for a little bit and then sell them to make some money. After I listened to them for a day I knew they weren't going anywhere. :laugh: I'd never owned any speakers with Kevlar drivers but, like I said, it made no difference to me. I couldn't care less what the drivers are made of as long as it sounds good. I bought a pair of Carver Amazing's at age 20 that I owned for 10 years and was happy with them and only sold them several months after I bought the 802's and right before I moved.