Sometimes people ask me if there is a way to replace headphones with smart textiles, sound coming out of a hood or from the fabric around the shoulder areas, near the ears.
What at first seems impossible is actually feasible with a bit of eTextile magic. Hannah, one of the most innovative personalities in the wearable technology space, published on her newly created Kit-of-no-Parts wearable tech website a possible way how to make sound with Fabric speakers.
Hannah picked up the work made earlier by Marcelo Coehlo’s paper speaker and the Accouphene Tuxedo created by Vincent Leclerc, added her own experience and expertise in wearable sound design and created an impressive overview, underlined with many examples on how to transform paper and fabrics into speaker.
The basic idea is to use a 2 dimensional spiral coil for the electric magnet instead of the more conventional 3D cylindrical coil wrapped around a magnet. To make this more exiting, the coil is integrated in the membrane, usually visible a cone shape but in this case, it is a swatch of fabric (or paper) which has the magnet function integrated and acts as membrane at the same time.
I was initially a little skeptic to get any kind of sound out of a 2D fabric swatch but to my surprise it works quite well. Sure, the sound output is far from even cheap speaker quality but just seeing and hearing fabric placed on top of a magnet starts emitting sound is amazing.
Inspired by Hannah’s design guideline I did some experiments myself and like to share some of my observations while working on fabric sound.
Firstly – as stronger the magnet, as louder the sound will come out. Using magnetic buttons I had lying around didn’t do a good job but some small but super strong magnets worked very well.
The size of the spiral in relation to the size (diameter) of the magnet: conductive traces, made in the different ways Hannah describes on her project page, of the spiral not covering the magnet have little effect on loudness or sound quality. If you have only a small magnet it does not help to make the spiral much larger.
The type of fabric also influences the sound quality and loudness: somewhat stiffer fabric gives better results than soft fabric. I got the best results using ripstop fabric which is a woven, lightweight nylon based fabric.
Got interested? Click over to Kit-of-no-Parts, get creative and listen to the Sound of Fabric.