Hello, As quoted below, some time ago Fons kindly provided the equations to extract virtual microphone signals from an ambisonic 1st order soundfield. I was wondering, is there a set of available and known formulas to extract virtual microphones from 2nd order recordings, taking advantage of the higher spatial resolution? Does it make sense or the formula applies the same only utilizing the 1st order part of it? I've seen some plugins doing spherical processing to achieve this but that's an area I'm not familiar with.
Thanks! Hector On Fri, Jul 19, 2013 at 10:37 AM Fons Adriaensen <f...@linuxaudio.org> wrote: > On Fri, Jul 19, 2013 at 09:56:40AM -0400, Hector Centeno wrote: > > > I'm trying to implement virtual microphones derived from first order > > ambisonic soundfields using Csound. I was wondering if anyone had any > > resources to share with equations that would allow me to achieve this, > > specifying azimuth, elevation and directivity of the mic. I've been > > analyzing Fons' code for Tetraproc (the Virtmic class) but I'm having > > difficulties understanding some parts of it (but I'll keep trying). I > found > > the paper "Has Ambisonics Come of Age?" by Bruce Wiggins which contains > > equations for doing this but it seems that it only takes azimuth angle in > > consideration. > > Given > > A = mic direction azimuth > E = mic direction elevation > D = directivity, [0...1], 0 = omni, 0.5 = cardioid, 1 = fig-8 > > and assuming your B-format is FuMA, compute > > cw = sqrt(2) * (1 - D) > cx = cos(A) * cos(E) * D > cy = sin(A) * cos(E) * D > cz = sin(E) * D > > and then the output signal for the mic is > > cw * W + cx * X + cy * Y + cz * Z > > 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 > -------------- next part -------------- An HTML attachment was scrubbed... URL: <https://mail.music.vt.edu/mailman/private/sursound/attachments/20190407/75b14eaa/attachment.html> _______________________________________________ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound - unsubscribe here, edit account or options, view archives and so on.
