You might not think junk from a builder's yard would be much use to an audiophile, but once you've seen these speakers you might well change your mind.
The brainchild of Daniel Ballou and industrial design studio Dashdot, these stereo speakers are made from old cinder blocks. They come fitted with a preassembled, pre-wired front panel, complete with a 5in driver, tweeter, crossover and input jack. There's also a back panel to seal the cinder block.
In other words, they're fully-fledged loudspeakers. But made of concrete.
This unusual material might actually help them, according to the designers. On the maker's product page, they point out that "concrete is a low resonance material that minimises vibrations and reduces the coloration of pure sound delivered by the drivers." Of course, we can't sing their praises sound-wise without testing them in our test rooms.
The cinder blocks might be expensive to ship and difficult to maneouvre because of their weight, but they can be picked up dirt cheap if you fancy making your own.
If you don't, the Cinder Speakers will sell for around $150 (£120) a pair. They're currently in the fine-tuning stage and should start shipping in the next few months.