>From: Lang Elliott <>
> At some point we discussed how to make a simple hydrophone using a condom
> pulled over a microphone.
>
Lang,
For starters, use an unlubricated condom!
Seal the open end around the mic cable (making sure to cover the XLR
connector) by making rings around the cable with electrical or duct tape.
WD-40 will remove any sticky tape residue afterwards. You could also
construct a cable with a couple of rubber "O" rings on it.
Tie the condom tightly to the mic cable in several spots, stretching the
condom over the rings.
I've only tried this method to a depth of 10 feet, and for about 15 minutes,
on a dynamic mic and it worked just fine (as waterproofing, the sound was
muffled). I didn't use an electret or condenser because I didn't want to
risk an expensive mic in salt water.
The main disadvantage of the waterproofing is the inefficient acoustic
coupling of the mic element to the water.
If you want a low-cost, good performance hydrophone, I like the AFAB. Less
than $150!
http://www.afabsound.com/
hope that helps,
Mark
________________________________________________________________________
________________________________________________________________________
|