On 2010-11-04, [email protected] wrote:
The interesting thing is, if I interpreted your earlier emails right, that having _some_ portion of 3rd order is better than having none at all.
Well, of course. Take for instance the 5.0 ITU setup, and try to imagine *not* how you would approach it from the level ambisonic point of view, but how you would go from that setup to ambisonic. What would be the optimization problem there, and the result?
Given what ambisonic and 5.0 do, they are pretty much incommensurable. So it's to be expected that any mapping between them would give rise to an infinite series. We must truncate that at some point, but just as Trinnov (for 5.1), Trifield/Barton (frontal stereo only), and even MAG (HDTV stuff, Vienna decoder, etc.) have told us over and over again, it's not just about the transmission order, or the order a given rig can support. In reality, it's always a product of those, and when those two are different, mathematics says you more often than not end up with an optimum which is an infinite series, which you have to truncate. Even if you only work with physical bounds, and not the perceptual, more complex ones we do.
That suggests that it might be worth looking at treating different third order components differently, as in Richard Furse's "discarded harmonics" approach (http://www.muse.demon.co.uk/ref/speakers.html)
That I think was an approach which mainly dealt with 3-to-2D transformations. But yes, singularity and instability in any sense should be brought within our optimization framework.
-- Sampo Syreeni, aka decoy - [email protected], http://decoy.iki.fi/front +358-50-5756111, 025E D175 ABE5 027C 9494 EEB0 E090 8BA9 0509 85C2 _______________________________________________ Sursound mailing list [email protected] https://mail.music.vt.edu/mailman/listinfo/sursound
