I’ve been making a few contact microphones using cheap ingredients for lo-fi live performance piece I’m working on. I’m no expert in electrical circuits, so I’m just following the directions Nicolas Collins lays out in his book Handmade Electronic Music.
I’ve used these instructions to make little piezo triggers before for Arduino projects and the like, so I’ve gotten pretty efficient at it.
I got a piezo element ($2.95 on Sparkfun).
Then, I took a guitar patch cable, cut it in the middle and soldered the element onto the cable (actually, I bought a 20ft cable for $10, cut it down the middle and soldered a piezo onto each half-cable, giving me two mics with 10ft lines).
Finally, I dipped the piezo in “Plasti-Dip” ($8.99 for a can of way more than I needed) to coat it. Ending up with this:
Although I made these mics for an “avant-garde” piece involving a block of wood, a saw, and some nails, I had the idea to test one of them out on my shamisen, just to see how well they might work as pickups.
Using painters tape (easily removable without damaging a surface), I tried attaching the mic to various parts of the instrument (including under the bridge and too the wood), until I settled on an unobtrusive point on the front skin.
Now, before I get all of you shamisen players’ hopes up that I’ve found a less-than-ten-dollar solution to shamisen amplification, give it a listen:
It’s not a terrible sound (putting my performance aside for the moment), but there’s not a whole lot of sustain. Of course, it’s a contact mic so that makes sense that we’re not getting any feedback from the space.
Here’s the same audio file with some DSP reverberation:
Better, but you only need to watch a couple of shamisen videos on YouTube, to easily hear that the sound is still not quite right.
Again, the instrument’s sustain seems too short (although the reverb covers this a bit), perhaps because the mic is on the skin rather than the wood.
Additionally, looking at a spectral analysis of the sound, we can see we’re not really getting a lot of the higher partials of the shamisen sound (including the “noise” of the bachi striking the string):
(You can also see a little bump around 60hz, which is some 60-cycle hum.)
So, in conclusion, this little mic may not be the solution to shamisen amplification needs in a pro-audio context, but it might still have some uses.
For example, hey, check out what I can do if I put the audio through my Rammstein plug-in in Guitar Rig: