> -----Original Message----- > From: Sursound [mailto:sursound-boun...@music.vt.edu] On Behalf Of > Fons Adriaensen > Sent: 25 November 2013 11:03 > To: sursound@music.vt.edu > Subject: Re: [Sursound] New Ambisonic VST Plugins - follow up Question to > Fons > > On Mon, Nov 25, 2013 at 07:31:33AM +0000, Bo-Erik Sandholm wrote: > [...] > > As a follow up question, would it be to my advantage to have the input > > signals "converted" to third order and stay there even for the decoding. > > Even if I only have a speaker rig of a circle of six horizontal and 2 > > speakers on the floor and 2 in the ceiling. > > Only if you expect them to be used at a place where a 3rd order > decode is possible and available. On your own rig you would still > have to use only the first order subset, as it can't be used for > 3rd order (not enough speakers). > [...]
It's certainly true that some decoding methods can become highly unstable when provided with an inadequate number of speakers and/or an uneven distribution. However, the Rapture3D decoders (including the TOA ones) do NOT have this problem. One of the core features of the Rapture3D decoder generator is its handling of arbitrary/irregular speaker layouts - a LOT of work went into this a few years ago. For the best quality output, you should feed these decoders with the highest order actual signal you have, regardless of how many speakers are present - the more accurate information these decoders have, the better they can perform. They will make some use of higher order components for almost all speaker layouts, although the amounts vary (the only exception I can think of now is mono, where only the W/omni component is used). That's all to say: if you have some good method and/or reason to increase the spatial detail of your tetramic material from first order to third order, perhaps through upsampling or other treatment, or as a side effect of processing, then that extra detail CAN make a difference, even on a small number of speakers. And personally, I don't consider ten speakers to be a particularly small number :-) Similarly, when forming a mix by simply panning mono sources into place, you can get significantly sharper results at third order rather than first, even if you only have a few speakers. Best wishes, --Richard _______________________________________________ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound
