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Re: csound surround module

Date1999-08-20 18:04
FromTorsten Anders
SubjectRe: csound surround module
Hi,

sounds really interesting. But how is the B-Format translated to n channels or
how is it encoded? (I read some of the ambisonics web-pages and found a hint on
convolution, is that true? Then it will hardly be possible to execute sound
movements...)

Torsten



On Fri, 20 Aug 1999 you wrote:
>i just want to clarify a few things about ambisonics (and why its so cool)
>
>- only 4 channels of data for full periphonic surround - and you can have
>ANY number of playback speakers in any location (obviously the more you
>have and the more equally spaced the better). 
>
>- it uses no psychoacoustic filtering like HRTF - it doesnt need to
>because it is trying to recreate the actual sound field in 3D space at a
>particular point (the center of the speaker array) -  its not using some
>kind of  "evil trickery" to fool your brain 
>
>- and as opposed to HRTF, localization within the sound field stays in the
>same place when you turn your head!
>
>- ambisonics (and B-Format[WXYZ] that it is normally stored in) is
>elegant and simple in principle, which has the bonus of being 
>computationally efficient - rotating sounds and other spatial
>manipulations are done much easier in ambisonics than HRTF.
>
>- full 3D ambisonics (B-fromat) takes up smaller space (4chnls) than dolby
>5.1(6chnls) - dolby 5.1 isnt reall "3D" anyway - no hieght -
>
>- if you ever get a chance to hear it, there is no comparison to dolby.
>with ambisonics, the speakers become "invisible" and you really are
>immersed in a "virtual" sonic environment.  
>
>- 
>

Date1999-08-21 01:12
FromRoland Morris
SubjectRe: csound surround module
torsten.anders@hfm.uni-weimar.de (Torsten Anders) wrote:

> sounds really interesting. But how is the B-Format translated to n channels or
> how is it encoded?

I found understanding the way the Soundfield (WXYZ) microphone works to
be beneficial.

http://www.transaudiogroup.com/soundfield/b_format.html

> >- 

LakeDSP do this virtually and Dolby are keeping a very close eye on them
to be sure.

http://www.headwize.com/pdfs/lake2.pdf
http://www.lakedsp.com

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