> Anyone using hydrophones to record in stereo? I was planning to use two
> hydrophones parallel to each other. However, not sure if both will remain
> still at one place and equidistant. I would love to know what others are
> doing.
Sabyasachi,
I've experimented with hydrophones in the past without much experience or
success with stereo. I put this down to the wavelength of sound in water
which is about 4.4 times the wavelength of the same sound in air.
Hydrophones tend to be omnidirectional but in shallow water the directional=
response is affected by echoes (again with a 4.4 factor) from the surface o=
r
river banks or bottom. I've used hydrophones in swimming pools which give a=
very differ reverberant effect to a large room of the same size. It sounds=
like a small very reverberant space.
If you are a swimmer, try listening out underwater to see what stereo you
can hear which is often not much. It sounds very different to listening in=
air, mainly because of the 4.4 effect, but you could experiment with
underwater baffles.
I have never managed to experiment underwater with a large "Jecklin disk" o=
r
a large board, but try a "binaural" setup with two hydrophones several
metres apart (theoretically 7.5 metres apart) which should give you "phase=
stereo".
David Brinicombe
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