Why are the diaphragms of pro woofers always made of paper?

[454Casull]

Is the only reason because they're expected to cover a wide range of frequencies (i.e. breakup must be smooth)?

[RJ]

They're just a tad behind the times...

http://www.partsexpress.com/pe/showd...TOKEN=71664086
http://www.partsexpress.com/pe/showd...TOKEN=71664086

Hemp and Aluminum cones.... & Neo...

Anyways, on 'Rock' CD's I like high effienciency drivers mixed with aluminum drivers for that guitar 'Growl' and aluminum 'Slam"...

[Cal Weldon]

The Selenium WPU 1507 QCF that I use in the Altec A7 cabinets is a quartz composite fiber. You can almost hit it with a hammer. When you rap your knuckles on it, it sounds like someone knocking on the door.

http://www.partsexpress.com/pe/pshow...=264-425&DID=7

[mashaffer]

Well this thread could get interesting (akin to a religious war if we are not careful). Here is my guess.

Pro equipment is made for a market that doesn't tend so much to the latest fads. Professionals want proven materials and construction methods that provide durability, predictable performance, graceful overload characteristics and easy repair in the field. Apparently paper or coated paper cones with cloth accordian surrounds meet these requirements better than foam halfroll surrounds and whizbang kevlar or metal cones can. For example a rigid plastic cone might be very good for a narrow range woofer in a hi-fi speaker used in the controlled environment of the livingroom where temperatures are steady and excursion is seldom streatched to the limit. Now how would that driver do in a wideband system that is exposed to searing heat, freezing cold and frequent overloads. Maybe OK, maybe not. Current pro driver systems handle that environment very well.

As other approaches prove themselves over the long term I suspect you will see more of them if they provide a significant benefit in the performance parameters important to pro applications. For example I think we are already seeing some use of rubber roll surround for extreme low frequency drivers where that provides a significant benefit.

Just my guess.

mike

[Cal Weldon]

Maybe paper sounds better

[454Casull]

Originally posted by Cal Weldon
Maybe paper sounds better

You went there. :O

[phase_accurate]

I own some JBL drivers (2206 and 2226) that were designed more than ten years ago and which are still available. They use paper-fibre composite cones like some expensive Scandinavian driver brand does.
AFAIK they used such cones before they were fasionable in the hi-fi area !
I think I don't have to mention that these JBL pro drivers are suitable for very high-quality reproduction.

Regards

Charles

[AndrewT]

Hi,
paper fibre offers some inherent advantages that are difficult to replicate with other cone materials.

Stiffness to weight ratio.
Damping.
Variable thickness.
Price to size ratio.
Availability.
Glue-ability.

[thylantyr]

Paper treated cones do sound very good over a wide frequency
range vs. other choices

[noah katz]

Very simple - efficiency from low density/mass.

Those pro drivers linked are much less efficient than paper cone drivers; I don't believe the Selenium's spec given its high Qe.

A few months ago I sat next to a speaker designer, and he said the biggest advantage of high tech materials is marketing appeal.