First 3-D Printed Records Sound Awful—And Amazing

From Wired:

It’s about the worst version of “Smells Like Teen Spirit” you could find. But it is awesome all the same for its totally unique medium. This particular LP is part of the batch of the first records ever to be created on a 3-D printer.

“It’s surprising how much you can deform and down-sample an audio file and still recognize it,” says Amanda Ghassaei, assistant tech editor at Instructables, who printed the record, and several others, including music from the Pixies, Daft Punk, and Radiohead.

Ghassaei used a state-of-the-art Objet Connex 500 printer to generate the disc. The whole process is possible because printing resolution has finally become high enough to create the audio-laden grooves for the needle to track and amplify. For her printed records, Ghassaei sets the machine to its finest setting, 600 dpi, with 16 micron steps, about the highest quality available on the market. But it’s still far lower resolution than on a vinyl LP, by a factor of 10 or so; hence the muddled sound that results in part from the needle responding to the layering of the printed plastic. Ghassaei used an 11 Khz sampling rate — the highest the resolution would allow, around 1/4 what you get from an MP3. Even at that low of a rate, the printer’s deficiencies cut off the song’s high-range tones.

To create the 3-D model for the record, Ghassaei essentially reverses the process of ripping an MP3. As the groove of a record is a microscopic image of the analog audio, she starts with the digitized waveform, using Python to take it directly from the MP3 file, and renders the shape of it into an STL wireframe using Processing, an open source tool that automates the file generation. She then uses the software to wrap it in a spiral on a 3-D 12-inch disc, varying the depth of the groove to match the waveform. Compared to a normal record, hers have increased amplitude and groove depth to account for the coarse resolution.

Continue reading the rest of the story on Wired