disclaimer: this user is getting seriously confused. On 02/28/2010 01:56 PM, fons@xxxxxxxxxxxxxxx wrote: > To reproduce the field of a real source, you need *all* > spatial harmonics, in theory (for a real point source) > up to infinite order. So An AMB system of order N must > not just recreate the harmonics up to order N, but *all* > of them. It will control some of them (but no more than > the number of speakers), and the rest has to be generated > by aliasing. i can see how a soundfield mike would capture (and thus include in the first-order signal)those aliased components, but then what about a panner? following your argument, shouldn't we add higher-order aliased components into a panner matrix? > A first order horizontal decoder with 4 speakers will > exactly control the levels of the 0, 1st and 2nd order > components, and the rest is filled in by spatial aliasing. > The aliased components are not exact of course, and that's > why localisation will be impaired if you move away from > the sweet spot. > > Now if you use e.g. 8 speakers to reproduce horizontal first > order the system controls components up to 4th order. If the > input is just first order, the 2nd and 3rd order components > will be zero, as will be all those that alias from them (5,6, > 10,11,13,14, etc.) The result is a field that does not match > well to that of a real source. hmm. i still don't see from this explanation why 1st order horizontal sounds worse over 8 speakers (or 12, for the sake of argument) than over just six, even if i'm in the sweet spot. best, jörn (who is about to crack open a can of fizzy InstaMath(tm) extra-strong) _______________________________________________ Linux-audio-user mailing list Linux-audio-user@xxxxxxxxxxxxxxxxxxxx http://lists.linuxaudio.org/listinfo/linux-audio-user
