[linux-audio-dev] High-order Ambisonic coder/decoder in JACK/LDASPA?

[Asbjørn Sæbø]

On Thu, Dec 15, 2005 at 08:33:34PM +0100, fons adriaensen wrote:
> On Thu, Dec 15, 2005 at 04:56:04PM +0100, Asbjørn Sæbø wrote:
> 
> > Some colleauges of mine do need a tool for coding and decoding of
> > high-order Ambisonic for their research.  They are aiming for seventh
> > order, played back over sixteen loudspeakers.  [...]
> > The first thing I would like to 
> > know is: Does anything like this already exist?  
> 
> No, and for some very good reasons.

Then we won't be reinventing the wheel, at least, which is good to know.


> Regardless of the JACK / LADSPA question, seventh order Ambisonics using
> 16 speakers is just ridiculous. Either it's horizontal only, and in that
> case using 7th order is just a waste of resources and effort (3th order
> will do all you want), or it's 3-D, and it that case 7th order requires
> *much* more than 16 speakers.

Well, I don't know much about Ambisonics, so I won't take this
discussion much further.  But I note that my colleauge working on this
is very much in disagreement with you.  According to him, you
theoretically need order 36 to achieve perfect wave front reconstruction
in a sphere the size of a listeners head.  (For a listener in the 
sweet spot and for frequencies up to about 22kHz, that is.)


Asbjørn