aluminum cone drivers

[larry7995]

I was wondering if there are differences in the sound coming from aluminum vs paper vs woven kevlar etc

 

[Adam]

Ahhh, shucks - you edited out the human skin reference.

It was kinda creepy, though...

 

[R-Carpenter]

Yes there are. Various drivers have their own acoustical signatures. Cone brake up happens on the different frequencies. Different motor structures and T/S make them all sound different. Cone stiffness plays a big part. In short, there's multitude of factors.
Of cause it doesn't mean that one is automatically superior to another. Some people prefer old fashion paper, some will love aluminum cones and I myself prefer carbon fiber and can't stand Kevlar. It all depends on crossover-enclosure design and goals of the designer.

 

[gene]

I believe the kevlar patent by DuPont prohibits speaker companies from using kevlar in their drivers. I think they all switched to fiberglass now. I also agree that kevlar is really not an ideal material for a driver. Although its strong, its too flexible which is something you don't want in a driver to maintain good linearity.

 

[larry7995]

Ahhh, shucks - you edited out the human skin reference.

It was kinda creepy, though...

It puts the lotion on it's skin

 

[larry7995]

Actually the speaker that got me wondering about the aluminum cones was the RBH 8300 SE/R. It looks like one heck of a speaker.
I am just going to have to get myself to RMAF next time and listen to some of these products - no excuses!

 

[WmAx]

I believe the kevlar patent by DuPont prohibits speaker companies from using kevlar in their drivers. I think they all switched to fiberglass now. I also agree that kevlar is really not an ideal material for a driver. Although its strong, its too flexible which is something you don't want in a driver to maintain good linearity.

Kevlar can be used in a way that results in a rigid cone. Focal used to make a high end mid/mid-bass line of drivers using a non-flexible resin filled (most kevlar cones simply use a loose weave - not a dense resin filled structure) double skin sandwich using kevlar and a very thin foam center core between the layers that acted as a dampening mechanism for cone resonance(s). The cone design pushed the break up mode relatively high, and with only moderate peaking (due to the high self dampening properties of the design). Granted, this is not by any means a normal kevlar cone design.

In addition, a specific weave pattern can be used to obtain specific properties that are ideal for an objective. B&W's FST mid-ranges are superb, and they use a specific weave pattern of kevlar to obtain both a resonance free passband and increased off axis response due to the driver acting as an effective controlled bending mode device.

-Chris

 

[CraigV]

While I was looking for a new set of speakers, one thing I wanted to avoid was bright & ringing sound. I had listened to some speakers with metal dome tweeters, and was not impressed. I had read good things about the IQ series from KEF which places an aluminum dome tweeter in the center of a titanium cone mid/low driver.
When I went to listen to them, I was sure they would be bright & shrill. Turns out, it was just the opposite – they’re smooth as can be. So yes, it is possible to have a neutral sounding cone driver made from aluminum or titanium.

But hey, why limit yourself to aluminum, Kevlar & such; why not wool:

(You know where they get virgin wool from – ugly sheep!)

Or a full range driver made from banana tree pulp:

And since wood is the defacto enclosure material, why not a real wood cone:

Then again, if you have a plasma display, why not a matching plasma driver: