Nicotine reidue on drivers

I forgot to add, vapor deposited Beryllium would never adhere to polypropylene without a surface treatment. Typically we would use an oxygen plasma treatment of the polypropylene before vapor deposition of a metal such as Beryllium.

I forgot to add, vapor deposited Beryllium would never adhere to polypropylene without a surface treatment.

 Well once the Beryllium was wiped off all that was left was a clear see though flexible cone under it.

Cheers George  

George, I was not disputing what you observed. In fact what you observed is what would happen if the Beryllium was vapor deposited onto an untreated or poorly treated polypropylene surface. I was just commenting on the need to introduce reactive bonding sites on the polypropylene surface for the vapor deposited Beryllium to bond with.

Why would you buy speakers from a heavy smoker?

What you have to think about is, can it be possible to stiffen a polypropylene cone just with vapor deposited Beryllium partials on it.
To be honest I don't think so, as the Beryillium particles would have no structural strength in either plane at all, unless it's spun or forged as in the GF-1's then there's no need for a polypropylene former under it.

Cheers George