> > > > > ------------------------------ > > Message: 3 > Date: Wed, 26 Jan 2011 14:26:07 -0700 > From: Martin Leese <martin.le...@stanfordalumni.org> > Subject: Re: [Sursound] Why do you need to decode ambisonic/b format > signals > To: sursound@music.vt.edu > Message-ID: > <AANLkTimZdCL=6o853d-str0vv2zxdkhejum4hzdnw...@mail.gmail.com> > Content-Type: text/plain; charset=ISO-8859-1 > > Geoffrey Barton <geoffreybar...@mac.com> wrote: > >>> From: Martin Leese <martin.le...@stanfordalumni.org> >>>> From memory, the theory behind Trifield >>> assumes either Blumlein XY, or pan-potted >>> multi-track mono. Perhaps Geoffrey can chip >>> in, or somebody can look at the paper >>> (reference below). ... >> >> It is not essential that the material is Blumlein or pan potted; that is >> just the way MAG handled a virtual 'test signal' in the paper; other >> recording techniques work ok too, but with varying results, much as they do >> over two speakers:-). > > Obviously different recording techniques will > work with varying results, and all will work to > some extent. The theory developed in the > paper, however, is more restrictive. > Specifically, MAG stressed the importance of > the decoder being energy preserving. But > there is little point in the Trifield decoder being > energy preserving when the recording > technique used is not. That would be closing > the stable door after the horse has bolted. > Blumlein M-S with a cardioid M, for example, is > not energy preserving.
but the decoder will preserve the energy as recorded. > > While energy preservation is not essential, the > paper seems to suggest it is desirable. yes, because it gives the best fidelity to the original musical 'balance'... whatever it originally was! The decoder was intended not to have an opinion about how the original should sound, unlike some variable matrix decoders :-) rgds, Geoffrey _______________________________________________ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound
