Rerurn to Romy the Cat's Site
In the Forum: Audio Discussions
In the Thread: Magico Mini or Jonathan Valin maxi?
Post Subject: Foam materialsPosted by el`Ol on: 12/13/2007
The Podzus-Görlich drivers use a special hard foam that was invented by Podzus in the 1930ies (Who would think about loudspeakers in first place after inventing a new material today?). I tried to find out more about it, but I failed. The problem is that all the good foams can only be produced as sandwiches. And since thin foils can only produced flat, the Podzus Görlich drivers are full cones that have to be manufactured by hand and look like garbage. Focal solved the problem by using glass fiber mash for their Rohacell cones. As the ATDs are Kevlar-reinforced, I believe they use epoxy foam. I´m sure they could have done better. Hartley achieve good results with solid epoxy plus titanium dioxide. Kea Audio claim to have good results with metal powder (don´t know what foam they use).Rerurn to Romy the Cat's Site