Audiophile speakers often go to extraordinary lengths to reduce cabinet resonances, but it's hard to think of anything more effective than carving the entire box from one solid hunk of rock. Audiomasons Design Works does just that, starting with big blocks of Indiana limestone.
I've seen other speakers made from poured concrete, and I remember a brand called Greybeard that made speakers using granite sheets, but the Audiomasons are the first I've seen cut from a single piece of rock.
Three models are available, and each speaker tips the scales at around 40-lbs. Prices seem to vary depending on where you look on their website, but they basically run from around $995 to $1,950 per pair. That might sound like a lot for a small two or three-way speaker, but think about how tough it must be to hollow out those rocks.
I wonder how they sound playing We Will Rock You, or I Wanna Rock?