Turn that trash into treasure with the Cinder Block Speaker Kit. Despite its technological vibe, this speaker uses real cinder blocks in its design. Thanks to the low resonance material, the cinder blocks actually minimize the vibrations produced by the speaker. This reduces the coloration of pure sound to deliver high-quality audio every time. Rather than shipping an entire cinder block, the Ballou team send out a fully assembled and wired front panel and a back panel with mounting hardware. Simply source a scrap cinder block and you can easily put the speaker together. The Cinder Speaker includes a 5-inch driver, a tweeter, a crossover, and even an input jack. Plug the Cinder Speaker into your turntable or even your smartphone and hear your music like never before.