--On 09 July 2011 14:04 -0400 Marc Lavallée <m...@hacklava.net> wrote:
So, is it possible to adapt a stereo recording to play on a horizontal ambisonics system, in order to get a better stereo image than with conventional stereo? A kind of "restored stereo" experience that ambisonics can provide because of its directional capabilities?
Two approaches that Michael Gerzon took are exemplified by the "Super Stereo" mode of the early ambisonic decoders, and the later "Trifield" system using three speakers; but neither of these is about attempting to generate a full circle from the stereo signal. A problem that arises, in any case, is that the result does depend strongly on the way the stereo recording was made - coincident mics (e.g. Blumlein), spaced mics (e.g. Decca Tree), or a reliance on mixing from spot-mics. As these record very different directional cues, a single process can't be expected to handle them all equally effectively.
As for 5.1 - there are a number of useful decoders available which can be used to reproduce ambisonic signals using speakers set up for 5.1; but the irregular spacing means inevitably that the results are not as good in some directions as they could be with the same speakers more uniformly spaced. Playing 5.1 signals through an ambisonic system is a matter of steering those signals as virtual sources at the required angles in a B-format signal; as with stereo, nothing is added to the experience because there is nothing extra to be found - but the reproduction will be less good to the extent that the sources expected when the 5.1 mix was done are being less precisely reproduced.
Paul -- Paul Hodges _______________________________________________ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound
