On 2012-03-06, Sampo Syreeni wrote:
rV can do with less. Those numbers are for rV and rE, simultaneously. You can't really do ambisonic without both working at the same time, so that's why those are the numbers being given out as the minimum.
And sorry for being too terse; it's been awhile since I last commented apart from FB and G+.
The reason why ambisonic doesn't work if not both velocity and energy optimization function simultaneously is that then you would have two different sets of directional cues which contradict each other. Psychoacoustically, that sort of thing makes your reproduced soundfield highly unstable wrt head movement (including rotation), weirdly incoherent, it lets the out-of-phase component of the LF rV decoding bleed through *much* nearer to the sweet spot than the integrated decode with rE as well, the sweet spot is narrower even with pure rV (it's the half whose sweet area consistently grows with more speakers; not necessarily so with the HF rE decode), and in particular the "crispness" of directional sources falls down dramatically; it all becomes a spacy mush, instead of directions being able to be acutely perceived.
Unfortunately I've never heard a sample signal set of what happens when you drop down from four to three speakers in pantophony, which would be the most classical case which Gerzon expounded. It could be simulated pretty well on an arbitrary pantophonic rig just by manipulating the B-format signal set, and of course arbitrarily well using the extra speaker detent signal early ambisonic work also mentioned, when quadraphonic ping-pong effects were the newest thing.
I wouldn't be surprised if that sort of a downgraded test, against the real ambisonic thing, might help to press the point home even today. Not to mention many others, e.g. for G-format... ;)
-- 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
