I have some experience using a pair of JRF hydrophones in small freshwater =
ponds. I was inspired to try hydrophones after hearing Tom Lawrence's Water=
Beetles of Pollardstown Fen. =0D
=0D
First I tried separating the hydrophones by about .5m and found that the tw=
o signals were completely different with no overlap of sounds at all. I sho=
rtened the distance to about 30cm but again found that there was no "stereo=
" just two disparate channels. Finally I tried rubber-banding the hydrophon=
es back-to-back and then I finally heard stereo- some overlap on each chann=
el of what I call "bacon frying"- bubbles and hisses from underwater plants=
and possibly invertebrates. =0D
=0D
I wanted to make a boundary array but out of what? Wood floats. I finally d=
ecided on using a small plastic storage container 6cm in diameter, with a h=
ydrophone on each side. It sinks, and I can deploy/retrieve it with a teles=
coping pole instead of tugging on the cables. I put a photo of my set-up in=
the files section titled "hydrorig.jpg". =0D
=0D
I have some samples here-=0D
=0D
https://soundcloud.com/varied-hush/jackson-botttom-underwater-sounds=0D
https://soundcloud.com/varied-hush/jbu2=0D
https://soundcloud.com/varied-hush/under-beaverton-creek https://soundcloud=
.com/varied-hush/under-beaverton-creek=0D
=0D
=0D
Happy Listening,=0D
Dwight Porter=0D
Portland, Oregon
|