Ceramic Speaker enclosures

In regard to a previous comment, I believe someone did make a pair of speakers from toilets, they gave a sort of horn loading. I've heard that plant pots are recommend for speakers, but I'm not sure how reliable the source was. I believe grout was used between epoxy granite and threaded inserts on some machine tools, I wonder how the drivers were mounted in the Jordan flagon. I'd be tempted to have a tension spring inside pulling the driver in place. Blu tac stops bells ringing, perhaps some rubber underseal would work. Can you mix slate powder in with your clay? Would it be possible to make a pot in a pot with a vent, after they're fired you could fill the gap with sand through the vent, then seal it up.
 
Lumping all ceramics together is as foolish as all plastics all metals, all wood, or even all paper. Some ceramics can be very strong. Some have higher modulus than others. Of course, anything can be laminated with various other materials to control the in-use properties.

My first over the top sub enclosure was a 12 x 12 tiles laminated with epoxy between two sheets of MDF. Very rigid. very dead. I was then going to do some sats but learned about baffle edge diffraction and built my next 30 years worth out of MDF for big fat radius's. I think a decorative tile inlayed to hardwood with an MDF liner might be quite good with some interesting aesthetic possibilities. Who ever said speakers should be brown boxes?