don't know if the zip file got through or not. Here are text versions. hopefully they come through ok. nick
On Oct 6, 2008, at 12:18 PM, Nicholas Mariette wrote:
hi Hans,
VBAP is probably better if you expect people to move around in the
installation space and you wish to pan individual sounds in
different directions. First order ambisonics works fine on 6 speakers, but it would be
more suited to immersive, enveloping ambient sounds, or a more
constrained audience.Horizontal VBAP will use only the nearest 2 speakers to simulate a
sound in one direction, while ambisonics decoding will generally use
all speakers for the same simulated sound source. Thus VBAP sounds
will often seem to "snap to speaker positions" when panning around
the circle, whereas ambisonic panned sounds will not reveal the
individual speakers as much, but the illusion will not work as well
away from the centre of the room.I like the description I heard recently from Bruce Wiggins on the
difference between VBAP and ambisonics - that VBAP is exactly
correct for panning a sound when it's in the direction of a speaker,
but quite wrong when panning exactly in-between two speakers.
Ambisonics on the other hand is "equally wrong" (to a lesser degree
than VBAP between speakers) for a sound in any direction.In many cases, the best spatialisation solution could be a mixture
of both VBAP (for directional sounds) and ambisonic (for spatial
ambience) - unless the audience isn't able to get too close to the
speakers, or you use higher order ambisonics.The IEM ambi stuff is all in Pd extended browser... I guess you've
seen that. I've attached some patches that I have for encoding to quad.Only problem is the latest 2 releases of Pd extended seem to have
problems loading mtx_*~ object. I got it working with Pd extended 0.39.3Output is for 4 speakers, but it's easy enough to change the speaker
specifications in the nmg_bf2quad~ abstraction - go into the pd
calc-matrix subpatch, make up a new speaker spec, print the decode
matrix and copy that back into the patch.Hope this helps.
Nick Mariette http://soundsorange.net
<test_ambi.zip>
On Oct 6, 2008, at 6:39 AM, Hans-Christoph Steiner wrote:
So I am working on sound for a permanent installation involving 6 speakers in a large circular room. Are 6 speakers enough to do anything useful using ambisonics? Or am I better off using the simpler vbap?
I am just starting to understand the basics of ambisonics, thanks to Florian's intro. I will be programmatically controlling the position of the samples, since it will be synced up with a video. So I don't think I really need the GUIs like cubemixer.
Are there any simple, working demos of the IEM ambi stuff?
.hc
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