Last weekend I decided to build my first hydrophone. I live on a lake and there are always interesting things going on around and in the water. Having been invited to also work on several art installations themed towards water, rivers and nature, I figured that something missing from my kit was an underwater microphone.
Not wishing to part with too much cash I decided to build my own. This was also because I wanted a stereo mic, and one built to my own specs. One built cheaply would also allow me the luxury of experimenting with several differing versions.
The microphone I decided to build was based on some Panasonic capsules hosted inside a set of stereo headphones, and then smothered in silicone. I also tied a fishing sinker to the mic so that it would submerge and be steadier in the water. I have to say I am extremely happy with my 1 hour build! The sound is so clear... and for only a few $$$.
I also used cable ties to keep both sides locked together so as not to have them hit each other in the water. The sinker is behind, and also held tight so as not to hit the microphones. The advantage of using the cable ties also allows flexibility in adjusting the angle on the microphones.