Dear Csounders,

I would like to announce the release of my spatialising- instrument 
coded in Csound. I use it to encode up to 20 moving sources in 2nd 
order Ambisonic.

Besides spatial encoding each source is equipped with

- distance information (ratio of global/local reverb/attenuation/ 
filtering)
- 6 dynamically changing specular early reflections (output is encoded 
spatially into 2nd order Ambisonic)
- another 6 dynamically changing diffuse early reflections (output is 
encoded spatially into 2nd order Ambisonic)

also each source is sent to a spatial reverb consisting of 12 
de-correlated reverberant sources spread equally around the 
unit-sphere, the output is encoded spatially into 2nd order Ambisonic.

Also Ambisonic Decoders coded in Csound may be downloaded. All the 
encoding and decoding of 2nd Order Ambisonic is based on the equations 
of Richard Furse and Dave Malham.  Thanks to the people on this list 
who supported me with knowledge and ideas.

The orc/sco/csd-files can be found at:
http://www.sonicarchitecture.de -> practice -> download

Best regards,

Jan Jacob Hofmann


sound         |         movement          |          object         |   
        space
sonic architecture       |        site: http://www.sonicarchitecture.de
spatial electronic composition     |    2nd order ambisonic music

I always found the concept of 'order' in ambisonics a bit confusing.
Can anyone explain it? Does 2nd-order mean 2-D?

Victor

At 15:32 30/09/2005, you wrote:
>Dear Csounders,
>
>I would like to announce the release of my spatialising- instrument coded 
>in Csound. I use it to encode up to 20 moving sources in 2nd order Ambisonic.
>
>Besides spatial encoding each source is equipped with
>
>- distance information (ratio of global/local reverb/attenuation/ filtering)
>- 6 dynamically changing specular early reflections (output is encoded 
>spatially into 2nd order Ambisonic)
>- another 6 dynamically changing diffuse early reflections (output is 
>encoded spatially into 2nd order Ambisonic)
>
>also each source is sent to a spatial reverb consisting of 12 
>de-correlated reverberant sources spread equally around the unit-sphere, 
>the output is encoded spatially into 2nd order Ambisonic.
>
>Also Ambisonic Decoders coded in Csound may be downloaded. All the 
>encoding and decoding of 2nd Order Ambisonic is based on the equations of 
>Richard Furse and Dave Malham.  Thanks to the people on this list who 
>supported me with knowledge and ideas.
>
>The orc/sco/csd-files can be found at:
>http://www.sonicarchitecture.de -> practice -> download
>
>Best regards,
>
>Jan Jacob Hofmann
>
>
>sound         |         movement          |          object         |
>        space
>sonic architecture       |        site: http://www.sonicarchitecture.de
>spatial electronic composition     |    2nd order ambisonic music
>
>--
>Send bugs reports to this list.
>To unsubscribe, send email to csound-unsubscribe@lists.bath.ac.uk

Victor Lazzarini
Music Technology Laboratory
Music Department
National University of Ireland, Maynooth 

Ambisonics uses spherical cone functions to approximate spatialization.
Second order adds the 'missing' spheres between the x/y/z spheres, third
order adds spheres between second order spheres, and so on. Third order is
probably a logical boundary. The calculation cost expands exponentially,
while the benefits are approximately inverse.

So a simple explaination would be higher orders produce higher
spatialization at the cost of higher computation.

I have often wondered if second order forms can be calculated from first
order for fixed geometries like the soundfield microphone.

Given the cost and geometry of typical rooms, evenly spaced 8 speaker arrays
for large audiences seem to be 'the answer' in 2d. Perhaps some math genius
can give us optimal calculations for a fixed geometry from a given ambisonic
source. As far as it goes right now, I sometimes prefer good old quad
recordings to bad ambisonics. This may be due to the limitations of my rig,
which are quite significant. When I can afford 6 more decent powered
speakers and a decent 8 out rack DA I will try to do ambisonics on a regular
basis in a large hall setting.

Michael Rempel

-----Original Message-----
From: Victor Lazzarini [mailto:Victor.Lazzarini@nuim.ie]
Sent: Friday, September 30, 2005 8:48 AM
To: csound@lists.bath.ac.uk
Subject: Re: [Csnd] 2nd order Ambisonic encoding, Spatial Reverb and
Early reflections


I always found the concept of 'order' in ambisonics a bit confusing.
Can anyone explain it? Does 2nd-order mean 2-D?

Victor

At 15:32 30/09/2005, you wrote:
>Dear Csounders,
>
>I would like to announce the release of my spatialising- instrument coded
>in Csound. I use it to encode up to 20 moving sources in 2nd order
Ambisonic.
>
>Besides spatial encoding each source is equipped with
>
>- distance information (ratio of global/local reverb/attenuation/
filtering)
>- 6 dynamically changing specular early reflections (output is encoded
>spatially into 2nd order Ambisonic)
>- another 6 dynamically changing diffuse early reflections (output is
>encoded spatially into 2nd order Ambisonic)
>
>also each source is sent to a spatial reverb consisting of 12
>de-correlated reverberant sources spread equally around the unit-sphere,
>the output is encoded spatially into 2nd order Ambisonic.
>
>Also Ambisonic Decoders coded in Csound may be downloaded. All the
>encoding and decoding of 2nd Order Ambisonic is based on the equations of
>Richard Furse and Dave Malham.  Thanks to the people on this list who
>supported me with knowledge and ideas.
>
>The orc/sco/csd-files can be found at:
>http://www.sonicarchitecture.de -> practice -> download
>
>Best regards,
>
>Jan Jacob Hofmann
>
>
>sound         |         movement          |          object         |
>        space
>sonic architecture       |        site: http://www.sonicarchitecture.de
>spatial electronic composition     |    2nd order ambisonic music
>
>--
>Send bugs reports to this list.
>To unsubscribe, send email to csound-unsubscribe@lists.bath.ac.uk

Victor Lazzarini
Music Technology Laboratory
Music Department
National University of Ireland, Maynooth

--
Send bugs reports to this list.
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