## ICST releases Ambisonics Externals for Max/MSP

Mar 30, 2006 at 8:12am

# ICST releases Ambisonics Externals for Max/MSP

#25142
Mar 30, 2006 at 9:11am

Thanks, a good work

( )
~ O ~ http://www.kineticsoundsystem.com
( )

#73677
Mar 30, 2006 at 2:23pm

Great objects!
Thanks a lot.

_____________________________
Patrick Delges

Centre de Recherches et de Formation Musicales de Wallonie asbl

http://users.skynet.be/crfmw/max

#73678
Mar 30, 2006 at 4:38pm

super-yeah, thanks a lot !

#73679
Apr 22, 2007 at 5:43am

would anyone be willing to explain how ambisonics works in layman’s terms? How would a four-channel ambisonic setup differ from quad panning based on simple level differences among four channels?

#73680
Apr 22, 2007 at 10:05am

Hi

To really get it you want to read the article in Computer Music
Journal (Myatt A and Malham DG: Three Dimensional Sound
Spatialisation Using Ambisonic Techniques, Computer Music Journal,
Vol.19 No.4, MIT Press, Cambridge MA,USA, 1995, pp58-70.

Also vist:www.ambisonic.net/

and: en.wikipedia.org/wiki/Ambisonics

Briefly, the point of ambisonics is that it is based on the
mathematical technique of sampling the surface of a sphere, whis can
be represented by four signals: X = front/back, Y = left/right, Z =
up/down and W = omni – for largely historical reasons to do with the
soundfield microphone this is known as B-format. A few simple
formulae involving sines and cosines (very easy to implement in Max
using cycle~ objects) enable the four signals to be decoded for any
number and configuration of speakers.

This technique was developed by the mathematician and sound expert,
Michael Gerzon in the 1970s, which led to the development of the
Soundfield Microphone, which enables a soundfield to be recorded and
encoded into B-format (A-format is the output of the microphone itself).

Level panning only works properly for speaker angles of 60 degrees or
less (and is also very dependent on correct location of the
listener), so if there are four speakers the average angle is 90
degrees, and level panning will always be sub-optimal. However,
ambisonic signals can decode correctly over four speakers, and they
don’t even have to be in an exact square. Larger numbers of speakers
will give greater accuracy for a larger number of people, as well as
enabling three dimensional positioning. Moreover, the same B-format
recording can be decoded for any number and positions of speakers, so
is easily adaptable to different listening conditions.

Much more details on the ambisonics website and the Wiki article (see
above)

On 22 Apr 2007, at 06:43, Joseph Grimm wrote:

> would anyone be willing to explain how ambisonics works in layman’s
> terms? How would a four-channel ambisonic setup differ from quad
> panning based on simple level differences among four channels?

Hope that helps

Lawrence

Lawrence Casserley – lawrence@lcasserley.co.uk
Lawrence Electronic Operations – http://www.lcasserley.co.uk
Colourscape Music Festivals – http://www.colourscape.org.uk

#73681

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