Second Reality is a legendary demoscene release by Future Crew, which won Assembly 1993 with its technical and artistic mastery. [Niv Singer] decided to give the classic demo a spin on a rather unconventional sound system with a particuarly techy twist.
Hard drives are great for storing data. They’re designed for this purpose. What they’re not designed for is acting as speakers, but you can hack them into acting that way if you’re so inclined. For this project, [Niv] pulled apart a whole stack of drives, so they could be repurposed in this way. The principle is simple enough—just feed audio to the coil driving the head, and it will vibrate and wiggle around, creating soundwaves in the air. It’s not particularly effective, and you get limited volume with a terrible frequency response, but that’s half the fun. [Niv] actually took some of this into account, too. Four Western Digital Caviar 500GB drives were chosen for this build, two for the left channel, and two for the right. Each channel had a crossover, allowing one drive to handle low frequencies while the other handled higher ones. For a further nice touch, the platters spin with the beat as well, with [Niv] providing a great explanation on how this was achieved with the use of some nifty PWM tricks.
Files are on Github for the curious. We’ve featured plenty of hard drive speakers before, too. Video after the break.

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