You should epoxy the leads when all's done to reinforce them (that's the white stuff); you need to solder the positive lead to the ceramic part which isn't very strong... I broke 5 of the first 6 I built.
Here's the Wikipedia microphone entry, incase I mention something unfamiliar. I don't want to alienate anyone.
First, I made piezo contact microphones...
You should epoxy the leads when all's done to reinforce them (that's the white stuff); you need to solder the positive lead to the ceramic part which isn't very strong... I broke 5 of the first 6 I built.
Here's a short audio clip of the contact on my cookie tin banjo.
Next I built a bass mic by rewiring a 6" or 7" speaker. I've only done small tests with it... it seems to pick up up to 12kHz, though it rolls-off heavily after about 1kHz. It has a huge spike around 80Hz. Mixing this mic with others should provide a very pleasing bottom end to bass sources.
Yamaha recently began marketing a fancy version of this idea, but I've heard studios have been doing this for ages.
My latest joy is this omni condenser based on panasonic's wm-61a electret cartridge. It runs on a 9 volt. I used the schematics provided by tape op's issue 16.
For the shockmount, I ripped out the centre part of a rotary fan cage and got nifty with some regular elastics.
This is my first condenser and I'm very happy. It's very sensitive, crisp, and flat in frequency response (here's an audio clip of the electret on my cookie tin banjo). It worked well on acoustic guitar and ukulele. But it's a bit noisy and cannot handle loud sound pressures, like drums. I'm working on a modification suggested by Mr. Linkwitz which should take care of these two problems.