On Thu, Sep 26, 2013 at 12:20:16PM -0500, Kan Kaban wrote: > Yes, I know there´s no ambisonics until there is. The idea of amplitude > panning, during A format stage, is to simplify an analogue path before > b-format exists.
A-format panning means that the panner has to emulate the polar patterns of four directional microphones pointing in directions corresponding to the vertices of a tetraheder. While this is possible, it will be more complicated that panning directly into B-format, with no addded benefit at all. > Quadraphonic (same to A-Format but without height?) No, very different. > keyboard or synth signals /// then an amplitude panner /// > then the A to B converter Conventional amplitude panning followed by encoding to B-format does *not* produce valid Ambisonic signals. > Well, if there is some kind of B-format analogue panner we would > also like to learn about it´s design, so we can actually see how > pointless it is. Both A and B-format panning require gains proportional to sine and cosine of some argument. It's possible to create a passable sin/cos pair using conventional linear pots over a 90 degree range (even a stereo panner does that). But you'd need 360 degrees in this case. Which means either very expensive non-standard potentiometers, or some non-trivial processing on VCA control signals. > The idea of panning quadraphonic packs seems easier to implement > BEFORE an A to B converter. And is completely useless. Again, quadraphonics converted to B-format is *not* Ambisonics. There is a good reason why Ambisoncs was almost forgotten until digital audio processing became a commodity. It's just a pain to do in the analog domain. And that's for only first order. Anything higher order would be madness if not done digitally. 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
