On Fri, Feb 08, 2013 at 09:14:54AM -0000, Richard Lee wrote: > > I;ve a suspicion that a Soundfield mic wouldn't behave > > well in such a weirdly reactive environment - i seem to > > remember chatting with Angelo Farina about this some years > > ago - anyone shed light on that?
It will pick up the pressure and velocity vector, no matter what they are. Angelo's remarks, IIRC, were about using intensity instead of pressure squared when thinking about e.g. AMB decoding. > There's quite a lot of work being done on using TetraMic > for Sound Intensity stuff. I first thought of using a > Soundfield for this when B&K introduced their SI wand > and I heard a really poor paper at IoA Windermere. Did > some theoretical work on it in the mid 80's which I'm > pleased to see confirmed in practice this millenium. > TetraMic's superior calibration helps here. > In a 'reactive' environment, you have XYZ much bigger > than W ... as you'd expect. No surprises there. A properly calibrated TetraMic makes an excellent intensity probe at low ad medium frequencies (up to 6 kHz or so). > > The business end appears to be a metal sphere, loosely > > comparable to a bathroom in size, which will soon be > > filled with argon. The presenter was able to climb inside > > to make the report, and the acoustics are, to say the least, > > "interesting". If it's indeed a perfect metal sphere it shouldn't be too difficult to *calculate* its response. > Presumably you know that you can't breath Argon and even Argon/O2 > mixtures can give strange physiological effects due to skin counter > diffusion of inert gases and other stuff .. even at 1 bar. Fon's > is a Scuba Instructor and can advise on the use of Scuba for the > 'presenter'. So are you IIRC - didn't you once try to feed Angelo to your local shark friends ? :-) I wouldn't advise breathing argon. Helium/nitrogen/oxygen mixtures are used at exceptional depths, creating the mickey mouse effect on speech. Ciao, -- FA A world of exhaustive, reliable metadata would be an utopia. It's also a pipe-dream, founded on self-delusion, nerd hubris and hysterically inflated market opportunities. (Cory Doctorow) _______________________________________________ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound
