Posted by: "Gianni Pavan"
> I'm curious about the design of the barrier(s) among two spaced
> mics. I don't understand well the relationships among the SASS design
> used by W.Knapp, the other barriers, including the Jecklin disk, and
> the use of "artificial heads". Why not using smooth, rounded
> barriers, like a sphere, or a cylinder ? And in such a case it would
> be better a sound absorbing barrier, or a reflecting barrier ?
Boundary mics generally depend on reflection from the barrier.
Jecklin disk depends on absorbing and stopping sound with the barrier.
Artificial heads reproduce aspects of the soundflow around our heads on
the way into our ears. Generally they are both barrier and reflection.
> Where I can find the theory behind all these different solutions ?
For boundary mics, including the SASS there is info on Crown's site.
This does not cover the Jecklin disk or artificial heads/binaural, which
are not boundary mics. The SASS is both a artificial head and a boundary
mic.
http://www.crownaudio.com/pdf/mics/127089.pdf
http://www.crownaudio.com/mic_web/mic-library.htm
The "New Stereo Soundbook" has a fairly complete coverage of standard
stereo mics including the Jecklin disk, artificial heads, binaural and
so on. Their section of boundary mics is weak, however. If you are into
stereo mics this is a very good reference.
http://www.stereosoundbook.com/
Many of the things possible you won't find exact discussion. This would
be true of most of Curt's designs. Many discussions barely even notice
things like the SASS or boundary designs in general.
I've considered designing a SASS like boundary mic based on Crown's
experimental "WSA" dish mic. Been watching for spherical section dishes
for that. Or maybe building a thermal molder to make my own. Not that I
need anymore projects right now.
Walt
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