are kevlar driver better, same or indiffernt to usuall speakers

leftwinger57

Hi guys,
As in a previous post I was tempted to buy a pair of Wharfield EVO PACIFIC 3s used for $300.Some of you directed me to Music Direct and showed me that new last years model for a pair went for under $600. I thought the price was good but still I did not hear them at all.In the interum I picked up a pair of Bose 601 series 1s which I am in the process of refoaming and the walnut cabinets are in great shape . My real question here is the Kevlar driver that Wharfdale and B&W uses much better than the speakers from the past.To me I would answer w/o knowing that Kevlar would last a life time and be much more durable. As far as the work on the 601s go I gutted them, cleaned thoughly the cabinets brought back the sheen w/ some good furniture polish and I'm just waiting for the surround kit to be delivered any day now.
I do have one important question to ask of you guys,yes the surrounds suffered from dry rot and that is common w/ 30 y/o speakers and will be addressed but I have 1 other concern that the paper cones them selves seem to be pretty dry.Is there any treatment to the speaker themselves to bring them back to near peak performance or if they work they work and that's it.If these are better than my Infinitys then they will go into 2-chl system duty and the Infinitys will be h/u to zone 2 on the Yamaha RX-V665.Please if any treatment is available let me know.Whether or not you guys approve of the Bose 601s have gotten the best reviews of any Bose product and for $20 I got a bargain here plus a project to keep me busy.Thanks, no put downs needed just advice please....

Mark_1042

I'm no speaker expert by any means, but as you say I think that kevlar would be much more durable than paper cones, given that the surrounds hold up. I think B&W also claims that the kevlar cones help to prevent distortion due to deformation of the speaker cone (or something to that effect). They've got an article and a couple videos on thier website as to why kevlar cones are better IIRC.

nhhiep

isn't stronger and lighter is the key reason?
like now they use carbon fiber in cars

cnh

Speaker design is a holistic process. You can't separate the specific materials used from the entire ensemble that includes cab volumes, damping, bracing, tweeters, crossovers, wiring and so on. Kevlar, in and of itself, is not necessarily the best material--see high end speakers that use paper or other synthetic materials that range in the 10s of thousands of dollars?

Is Kevlar "durable"? Yes, but look at old Polk speakers from the '70s and '80s (most of their drivers are also still functional). I have speakers four decades old made of paper products that are perfectly fine!

It is also true that Kevlar is used because it is lighter and more rigid so that it can keep its form under the stresses of oscillating at many cycles per second. Since it is lighter and does not deform much it can also respond more quickly and also "stop" vibrating more quickly.

As far as your concerns about the Bose speaker cones, there is a guy at Audiokarma who is the speakers repair "guru". I think his handle is GordonW (Gordonw). He's seen and repaired more speakers than either of us will ever have or listen to. Perhaps you could get a note to him?

cnh

Face

leftwinger57 wrote: »

My real question here is the Kevlar driver that Wharfdale and B&W uses much better than the speakers from the past.

Yes, generally modern drivers have less distortion. And high end drivers such as B&W's Kevlar midrange have amplifier like distortion(less than 1%) in their passband. As for materials, such is possible with other materials such as paper, magnesium, aluminum, ceramic, etc... The motor and overall design(cone, surround, etc...) is more important than the "material" the cone is made of.

zingo

Cone material is just one piece in the overall voicing and sound that a driver creates. The ideal driver is infinitely light and infinitely ridg which is why companies have experimented with "exotic" materials like kevlar, diamond, beryllium, etc.

However, design ideals don't equal sound quality and musicality. As stated above, the entirety of the design is more important than the driver material. For whatever reason, most of the designs I've liked have been paper cones so who knows.

Face

You may enjoy the higher even order distortion that's common with paper cones.

FTGV

zingo wrote: »

As stated above, the entirety of the design is more important than the driver material. For whatever reason, most of the designs I've liked have been paper cones so who knows.

Cones made from stiffer materials such as Alum.,Magnes. and Kevlar etc. can have severe break up or resonant modes at the top of their operating ranges.These modes if severe enough need to be dealt with as part of the crossover design or they can/will impart their own flavour of colouration to the mix.In general paper cones are much better damped thus better behaved so don't exhibit the severe break up modes.

FTGV

For example this SEAS magnesium cone has a big peak in it's response just shy of 5k. http://www.madisoundspeakerstore.com/seas-woofers-6-7/seas-excel-w18e-001-e0018-7-magnesium-cone-woofer/

but in comparison this SEAS paper cone exhibits a much smoother roll off at the top of it;s range.http://www.madisoundspeakerstore.com/seas-woofers-6-7/seas-prestige-ca18rnx-h1215-7-coated-paper-cone-woofer/