(Credit: Amanda Ghassaei)
Instructables' Amanda Ghassaei has created a technique for turning digital audio files into 3D-printable models of records.
If your thought is that a record pressed on a 3D printer would sound pretty terrible, you'd be, well, absolutely right. As the needle finds the groove, the familiar vinyl crackle is joined by a weird warped squeal before the nevertheless recognisable opening chords of Nirvana's "Smells Like Teen Spirit" arrive on the scene.
The 33rpm record is the work of Ghassei, who has spent the last year tooling around with audio projects, trying to re-create digital audio signals physically using simple tools and low memory.
"Through these projects, I've learned that audio is a very resilient medium; it can take a fair amount of abuse (in the form of distortion and compression), while still maintaining most of the integrity of the original sound," she said. "The key is as long as you loosely approximate the overall shape of an audio signal, the output will sound reasonably recognisable."
Turning a digital sound file into a record is a multi-step process. First, you need to create the 3D mould. To do this, Ghassaei converted her stereo file into a WAV, combining the left and right channels around a central zero.
The resulting integers were then exported to a TXT file, which data could then be imported into Processing for conversion into a CAD STL file, wrapping the waveform into a grooved 12-inch 33rpm spiral.
To print the record, Ghassaei used an Objet Connex500, one of the highest-resolution 3D printers around. However, even at 600dpi on the X axis and 16 microns on the Y axis, the resulting record is still significantly lower resolution than a vinyl record.
Another problem is compression. Even stripped right down to the bare bones, the largest file currently possible is around 250MB, or a little over a minute's worth of audio. However, Ghassaei believes that the potential is there for six minutes.
Even with all of the distortion and static, even with the small file sizes, there's something quite wonderful about listening to Ghassaei's recordings. Perhaps it's the combination of old technology with new, 3D printing with records; perhaps it's that Ghassaei managed a feat of remarkable reverse engineering; or perhaps it's that we're tremendously excited to see the direction 3D printing is heading in.