They look absolutely gorgeous!
What are you talking about "dampening foam"?
You mean the yellow fiberglass looking material behind the speaker?
I don't think that can be surpassed as it is optimized for the driver and from reading thru some Fostex t50rp threads that would relate to any internal reflections so would alter soundstage,
BUT I Do think the metal cup or internals could possibly be dampened slightly but the design overall leave little room for modifcation I assume the materials are highly optimized already. .
Yeah, I meant the fiberglass material in the back.
Sorry, I keep thinking "foam" for some reason.
I'll play around with it (by adding more materials in there) and see how it changes the sound. Probably not as much as I'm hoping to hear, but it'll be fun anyway.
Alternatively, adding filters to the ear pads may be fun as well... seeing as the ES10 is really sensitive to different types of ear pads and materials.