What are the differences in Tweeter materials?


I am curious,

Is there someone that could tell me about the differences between the various materials out there that are used to make tweeters? Both soft and metal type.

What are the materials used in each and what are the sound differences both positive and negative?

Soft Dome Tweeters:
Soft dome, Silk dome, Cloth dome, Polymer dome, Polyamide dome and Textile domes.

(I am very confused in particular between Soft, Cloth, Silk, and Textile?)

Metal Dome Tweeters:
Aluminum, Titanium, Beryllium, Diamond coated, domes and inverted.

Thanks!
mezzanine

Showing 1 response by kijanki

Steve Mowry says in the article "The Whole Truth About Beryllium Diaphragms: -

"For a given geometry the first bending (break-up) frequency is proportional to the material Speed Of Sound, where the speed of sound within a material is defined as the square root of the YoungÂ’s Modulus divided by the Mass Density, (m/s); the higher the better. However, the Mass of the diaphragm must also be considered. Then the ratio of the Speed Of Sound to the Mass Density can be used as the materialsÂ’ acoustic figure of merit, (m4/kg/s); the higher the better."

After that he shows values of "Acoustic Figure of Merit" for different material (higher the better)in m4/kg/s

Berillum - 6.97
Diamond - 4.92
Aluminum - 1.86
Titanium - 1.13
Steel - 0.63