US source of Panzerholtz?

Agreed that constrained layer damping works by converting vibration to heat, but don’t agree that it is more effective when both layers are less stiff.

A counterexample to the ASC assertion is industry-leading Quietrock 545 acoustic drywall, with an embedded layer of sheet steel. Works very well in my listening room. This is consistent with my understanding, that what matters is speed of sound in the material. Adjacent materials should have very different sos. I have read that panzerholz sos and aluminum sos are similar (6000 m/s), but have not tested it, though I keep meaning to.

OH - now I think I see what ASC is talking about. Perhaps they are talking about vibration THROUGH the wall material, whereas what we are interested in is vibration ALONG the plinth material.

All the same, I wouldn’t want my walls flexing like a 10 cent woofer.

I have no personal experience with Corian, but found the following comments when considering a plinth for a SP-10 Mk 2.

First, apparently Corian includes flakes of aluminum in the compound.  But there is no specification for size or quantity of those flakes, so the resonance characteristic can vary from one brand to another.

Second, it is mentioned in the Direct Drive site and is not recommended for plinths, too lifeless or laid back sonically.

Your mileage may vary.

pryso

... apparently Corian includes flakes of aluminum in the compound.  But there is no specification for size or quantity of those flakes, so the resonance characteristic can vary from one brand to another.

That can't be correct, because DuPont is the sole manufacturer of Corian and has trademarked the name.

Corian does not have flakes of aluminum in it. It is alumina trihydrate and an acrylic polymer. The different manufacturers of solid surface material use different polymers. Alumina trihydrate is a byproduct of bauxite as is aluminum ore. There are now about 20 different manufacturers of solid surface material now including the quartz versions. All of it is very heavy and stiff. Laminated to MDF it makes a marvelous plinth or baffle board. You just have to have the tools and knowledge to work with it. It is also extremely messy. The dust sticks to everything. You have to vacuum your ceilings after a project. You have to use special adhesives that require special guns which are different for any given manufacturer and the adhesives are color specific. For the usual home crafts person it is just plain hard to deal with it all.