Paper Cones

[Edbo2]

Is paper still the best material for drivers? I have had speakers with bextrene, paper and now metal. May be nostalgia or what but are paper cones best?

 

[NSA_watch_my_toilet]

Paper is always a good component, until today but they are not the only one. The main advantage is the ability this to be repaired. Reconing an old paper cone is a current thing. Recarboning a carbon cone is... something I never heard of. But carbon, metal, plastic, ceramic and kevlar are all good materials for making drivers.

 

[nopiano]

It still seems to dominate, even though they are invariably treated in various ways. Don't forget flax in your list, which Focal seem to favour.

I'm now of the view that the material per se is less important than how it is implemented.

 

[Al ears]

It still seems to dominate, even though they are invariably treated in various ways. Don't forget flax in your list, which Focal seem to favour.

I'm now of the view that the material per se is less important than how it is implemented.

Agree. Paper is utilized in larger transducers because it is adaptable and cheaper. The benefits over other materials are debatable.

 

[Gazzip]

It still seems to dominate, even though they are invariably treated in various ways. Don't forget flax in your list, which Focal seem to favour.

I'm now of the view that the material per se is less important than how it is implemented.

Agree. Paper is utilized in larger transducers because it is adaptable and cheaper. The benefits over other materials are debatable.

There is an interesting interview on YouTube with PMC's Peter Thomas on the subject of speaker materials. He is of the view that doped paper is stiffer and lighter than any other material so ideal for drive units. He says he would change materials if there would be any perceivable improvement but there isn't so he thinks paper is still numero uno.

I can't cut and paste in to posts on this forum unfortunately but if you want to watch it it the title is:

Peter Thomas of PMC Interview - Part 2 - The DSP Project

Part 1 is also worth watching...

 

[Gray]

I've had Bextrene and Kevlar, now I'm back with paper.

I agree with what others say about implementation. If you've got nothing better to do, have a look at my user review of PMC twenty 21 and its use of a 'plain old paper driver'.

 

[Andrewjvt]

I've had Bextrene and Kevlar, now I'm back with paper.

I agree with what others say about implementation. If you've got nothing better to do, have a look at my user review of PMC twenty 21 and its use of a 'plain old paper driver'.

There is a paper driver and a paper driver. Not all equal

 

[BigH]

Loads of technical problems with Kevlar. Not sure its worth it, who else but B&W use it?

 

[Gray]

I've had Bextrene and Kevlar, now I'm back with paper.

I agree with what others say about implementation. If you've got nothing better to do, have a look at my user review of PMC twenty 21 and its use of a 'plain old paper driver'.

There is a paper driver and a paper driver. Not all equal

Indeed. And, of course, I'm not saying that any (rigid) cone material guarantees a standard of performance (good or bad) in the finished speaker.

 

[Gray]

Loads of technical problems with Kevlar. Not sure its worth it, who else but B&W use it?

Quad did use Kevlar. Not any more though?

 

[Electro]

It still seems to dominate, even though they are invariably treated in various ways. Don't forget flax in your list, which Focal seem to favour.

I'm now of the view that the material per se is less important than how it is implemented.

Agree. Paper is utilized in larger transducers because it is adaptable and cheaper. The benefits over other materials are debatable.

There is an interesting interview on YouTube with PMC's Peter Thomas on the subject of speaker materials. He is of the view that doped paper is stiffer and lighter than any other material so ideal for drive units. He says he would change materials if there would be any perceivable improvement but there isn't so he thinks paper is still numero uno.

I can't cut and paste in to posts on this forum unfortunately but if you want to watch it it the title is:

Peter Thomas of PMC Interview - Part 2 - The DSP Project

Part 1 is also worth watching...

I've done it for you *smile*

https://www.youtube.com/watch?v=Xz45IYZQMf0

 

[Vladimir]

It still seems to dominate, even though they are invariably treated in various ways. Don't forget flax in your list, which Focal seem to favour.

I'm now of the view that the material per se is less important than how it is implemented.

Agree. Paper is utilized in larger transducers because it is adaptable and cheaper. The benefits over other materials are debatable.

There is an interesting interview on YouTube with PMC's Peter Thomas on the subject of speaker materials. He is of the view that doped paper is stiffer and lighter than any other material so ideal for drive units. He says he would change materials if there would be any perceivable improvement but there isn't so he thinks paper is still numero uno.

+1

Same words from JBL.

 

[NSA_watch_my_toilet]

Loads of technical problems with Kevlar. Not sure its worth it, who else but B&W use it?

Quad did use Kevlar. Not any more though?

KRK, Behringer, M-audio and Presonus.

 

[Edbo2]

Currently I own a pair of Kef Q series with the metallic Q driver and at times the reproduction can sound, well chromium plated

 

[Gazzip]

Currently I own a pair of Kef Q series with the metallic Q driver and at times the reproduction can sound, well chromium plated

I had Kef R300's, 500s and then 700's through my system a few years ago. Great sounding speakers generally, although I found male vocals to have a somewhat metalic edge at times. I actually posted about it on here at the time. Having since auditioned the Blade and Blade 2 and (to my ears) found the same harshness I have concluded that the Kef sound signature just doesn't suit me.

 

[Edbo2]

My previous speakers were JPW AP2 which I wish I still owned. They had Vifa drivers in a sealed enclosure. I found the bass lacking and got rid of them but tight bass is a feature of sealed boxes. All I needed was a more powerful amp to compensate. We live and learn!!

 

[Diamond Joe]

I don't think I've ever known what any of my speakers are made of.

Could someone tell me what my Neat Motive 2 speakers cones are made of by any chance?

 

[matthewpiano]

Rega's R125 bass/mid drive unit, used on my RS1s, has a paper cone and they are certainly very natural and effortless sounding speakers. However, my Dynaudio DM2/6 use a magnesium based MSP material and they are also superb small speakers. The Mordaunt-Short Mezzo 2s I used to have also sounded lovely and not at all bright despite using a metallic material on the bass/mid unit. This really holds up what others have said - the implementation is rather more crucial than the material.

 

[BigH]

I don't think I've ever known what any of my speakers are made of.

Could someone tell me what my Neat Motive 2 speakers cones are made of by any chance?

Paper it seems.

 

[TrevC]

Loads of technical problems with Kevlar. Not sure its worth it, who else but B&W use it?

What technical problems are those?

 

[Vladimir]

Much ballyhoo is made about the fact that Kevlar is used in bullet proof armor, which incidentally, has no mechanical similarity as to why Kevlar works well for stopping bullets. The high internal friction of the material that damps out free vibrations is not the mechanism by which the force of an instantaneous impact is redistributed to prevent penetration of a projective. Marketing types don’t understand the difference and they don’t really care as long as it sounds impressive, and they hope the consumer doesn’t understand either.

Chemically, Kevlar is a member of the nylon family of polymers and is known as poly-para-phenylene terephthalamide or para-aramid. During manufacturing, the material is drawn into a fiber that aligns the polymer chains giving the material its mechanical properties and orthotropic behavior. Kevlar is available in three grades of increasing tensile strength and modulus: 29, 49, and 149; Kevlar 49 is the most common. For use in composites, Kevlar fibers are often woven into a textile and laminated in a polymer matrix.

The challenge comes in the form of the substantially more complex and difficult to predict mechanical behavior of woven composites. Most materials used for cones are isotropic, meaning they exhibit behavior that is mechanically similar in all directions. Radially around the cone, the uniform behavior reduces the number of mathematical variables and equations which making them relatively simple to predict. Various plastics like polypropylene (which is homogeneous), and even paper (which is an inhomogeneous short fiber composite), behave as isotropic macroscopically. Woven long fiber composites exhibit substantial mechanical variations at angles relative to the fiber axes. The discontinuous geometry of the woven fiber structure complicates the mathematics that have to account for independent properties of the constituent components of the textile, sensitivity to weave geometry, yarn construction, and bonding between the fibers and the matrix, and anisotropic behavior of the composite with respect to loading orientation.

For more on this topic, see the forthcoming: A Primer on the Mechanics of Composite Kevlar Drivers.

At no point in the above discussion am I saying that these challenges cannot be designed for with a satisfactory acoustic result or that B&W’s expertise is not such that they cannot overcome these challenges. Quite the contrary, as B&W seems to successfully taken advantage of this behavior.

Kevlar drivers have often been attributed with a slightly richer sound by many professional and amateur listeners. With circumferential variations in stiffness, the cone will have slight variations in the uniformity of sound radiation with the more flexible areas lagging the stiffer areas. This causes time dependent variations in deformation and movement of the cone and subsequent variations in the air pressure distribution of the acoustic emissions from the cone. What this means is that there will be just a little bit of phase shifting about the frequency of any given forcing function.

My current working hypothesis is that this is the source of the perception of the slightly fuller sound associated with Kevlar drivers used for midrange. These frequencies are where instruments reveal their timbres. Current psychoacoustics research into the precedence effect suggests that the ear will integrate slight phase discrepancies and interpret this as richer sound. Perhaps this can be thought of as akin to a chorus sound processing effect where a fuller sound is generated by introducing phase offsets in the signal that, as in a real chorus of voices or instruments, gives the listener the perception of a greater number of performers.

Source

 

[pyrrhon]

Proac studio line went back to doped paper in the latest iteration. Awesome result and noticeble improvement.