Serious question looking 4 serious responses - Why is Polk so hung up on Poly cones?

[VR3]

I know Poly cones are actually a very good material - even Brian Cheney gives it a B.

Just curious what Polks reason for using the material is?

Why not try carbon fiber or kevlar, etc?

[BlueFox]

Or machined from solid aluminum!

I suspect cost is a major factor in these decisions, but that is just a guess.

[AsSiMiLaTeD]

They have lots invested in research over the years and they're a cost effective solution, why would they consider anything else?

[Face]

Every material has plusses and minuses.

Look at ScanSpeak, most of their drivers are paper. Audiotech uses plastic, Accuton uses ceramic, aluminum, and diamond, and Seas is all over the place.

The overal design of the driver is more important.

[tonyb]

Maybe the question should be why your so hung up on picking apart polk speakers. C'mon Trey, you know the answer to your own question. Polk doesn't set out to mod every little piece of their speakers, instead focusing more on the final product at a given price point. They also have to consider long term reliabilty issues when selecting parts, something that newer more sophisticated parts haven't established yet. Too much is at stake to the company's reputation.

That said, I'm sure Polk is constantly trying out new/better parts to be implimented at later dates. Thats what R&D does. You can always ask why not try this or that part, but as far as we know, who's to say they haven't ?

[mhardy6647]

It is a serious question, and this is a serious response - but not an answer.

There's no free lunch.

I prefer the sound of paper products; they don't have the crazy-ragged out-of-band breakup behavior that the light/stiff materials (ceramics, metals, Kevlar, etc.) do. The latter require what I would categorize as draconian cross-over solutions to be rendered tolerable. From my perspective and to my sonic tastes, the "high tech" cone materials offer more drawbacks than advantages relative to good ol' paper.

[nooshinjohn]

I prefer doped paper cones myself, or mylar diaphrams stretched over magnetic plates.:smile:

[mhardy6647]

I've got some Saran diaphragms suspended in an electrostatic field that acquit themselves rather nicely, especially in the midrange.

Speaking of midrange, I will confess to an abiding affection for aluminum diaphragms when they're inside of certain classic Altec compression drivers.

[gdb]

A whole new twist to the paper or plastic question:afro

[rebuy]

Like most of you, I've owned speakers made out of all kinds of materials and each had their qualities and drawbacks.
I like the sound my Poly Polk speakers make.

As far as using poly for speakers, making this material for speakers apparently has it's advantages. It's much more versatile as far as forming drivers is concerned. You can form drivers with different thicknesses throughout one cone to give the driver the sonic signature of the system and to cut down on driver resonances.
In the case of the LSI system the cones are aerated for the LSI sonic sound. A different mix than the RTI cones I use.

I think Polk has done a lot of research with poly cones and knows how to design them well.


I also prefer my coffee aerated, not stirred.