the worm-mic reminds me of this installation in Brazil "Som da terra" (sound of the earth) at the garden/gallery "Inhotim" - it's by American artist Doug Aitken - where 5 mics are lowered 202m down into the earth. Here's a video showing the installation and an EV re20 protected in a plastic water bottle. Someone describes the sound as being violent and noisy sometimes and other times more peaceful.
http://www.youtube.com/watch?v=ITr5NzDSqlw Em Ter, 2013-02-19 às 21:46 +0000, Dave Malham escreveu: > The trouble with the sort of materials used in condoms is that they > are inherently stretchy. Under any sort of pressure (more than a quite > small depth of water) the material presses through any holes and > either (a) rips or be (b) comes into contact with the diaphragm which > is potentially almost as big a disaster. That's why the first DIY > hydrophone I linked to uses an electret capsule immersed in oil in a > canister. I have uses both condoms and cling film to waterproof > microphones but only really for splash proofing. For those situations > you can measure the mic before wrapping and after so that compensation > can be made for the inevitable resonances. Probably not possible for > underwater systems without the the same problems of needing a > calibrated source and a lot of underwater space which, given the fact > that it probably won't be possible to use the assembly at any sort of > depth, is not going to be easy. > > Dave > > PS The wackiest thing I ever sealed a microphone for (with cling film) > was to listen to worms under the ground for a biologist who was trying > to find a way to assess the number of worms in a given volume of soil > without crushing them up with the soil and extracting the (now dead) > biological material. > > On 19 February 2013 17:48, Martin Leese <martin.le...@stanfordalumni.org> > wrote: > > Fons Adriaensen wrote: > > > >> Don't know what Len will think of it, but putting a Tetramic > >> (or any such mic) in a plastic bag isn't likely to produce > >> anything usable. Basic problem is that the acoustic impedance > >> of water is around 3400 times higher than that of air, so the > >> water/air interface will reflect almost all energy. You need > >> a transducer that is more or less matched to the acoustic > >> impedance. > > > > I have read that the standard trick is to use a > > condom. However, I puzzle whether this would > > work with a Tetramic. > > > > Regards, > > Martin > > -- > > Martin J Leese > > E-mail: martin.leese stanfordalumni.org > > Web: http://members.tripod.com/martin_leese/ > > _______________________________________________ > > Sursound mailing list > > Sursound@music.vt.edu > > https://mail.music.vt.edu/mailman/listinfo/sursound > > > _______________________________________________ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound
