| Dear Michael and list,
for my approach of spatialized composition and music it is crucial
that the phantom image is as precise as the sound coming directly from
the speaker. Ambisonic is excellent in producing fairly stable phantom
images, even for listeners off-center, with less speakers than in usual
amplitude panning. I do anyway regard amplitude panning as not
convincing at all for the task of producing phantom images when it
comes to surroundsound or even surroundsound with height. There must
not be a blurred image or a jumping from speaker to speaker as the
sound moves around. I needed a method being capable to move sounds
completely independent of the speakers. Ambisonic does this job
excellent.
I guess with six speakers and 2nd Order Ambisonic it is pretty easy to
get stable phantom images for a set-up in a plane ( without height).
For First Order, four should even be enough. The higher the order, the
more speakers are needed but six are definitely sufficient for
reproducing second order Ambisonic at a plane. Eight speakers should
make the image even more precise, though. I have done several concerts
with various speakers for audiences with different amount of people.
The last I did has been at the ZKM at Karlsruhe/ Germany during the
Linux Audio Conference in April 2005 with about 100 people listening.
Eight speakers set up in the shape of an (a bit distorted) octagon were
used. You can see photos and brief descriptions of most of the venues
at my pages at the subject "performance" and "more infos and pictures".
Some people among this list participated that concert too, among them
John Ffitch. I guess spatialisation, distance clues and phantom images
worked very well and I guess the listeners would agree. Comments on
that concert welcome!
For me it starts to get most interesting, if height is included. Here
at home, I have a rig with eight Genelec 1030 set up as a cube (one
speaker at every corner of the cube). Although the numbers of speakers
should be higher for a reproduction of 2nd order with height component,
I do still not experience any holes of perception of sound in-between
the speakers. This may be due to the fact that they are very good
monitors. With less precise speakers at least 12 might be needed for a
fine reproduction with height. Dave Malham can explain eloquently and
mathematically correct the minimum number of speakers for any order and
type of setup (on a plane or with height) but I do not care too much,
as for me money is the limiting factor anyway. Also, as you mentioned
there is the transportation-problem and the time it takes to make a
proper setup, so I prefer to use the speakers of the venue, as long as
they are sufficient in quality and number. Still it is difficult to
find venues which are capable and willing to perform surround, as it
takes more effort. Also the effort of composition is much higher, as a
whole choreography of movement and location has to be created and the
volume of the sound ofcourse then changes according to its distance.
Creating and performing surroundsound has always been for me the
opposite of making "easy money". Still I find it very, very intriguing
and and a hundred times worth the effort.
I can not tell if Ambisonic will take over professional sound
production. It depends on what you want. It is a matter of quality and
effort. If you want a format easy to use, 5,1 surround is much better.
Just insert the DVD, press play and off we go. But this medium has its
strict limitations, and if you want (or need) to go beyond, you may
consider using 2nd Order Ambisonic, as long there is a demand for more
precise localization. Ambisonic is for me comparable with Linux and
Beta-video. All three systems have their advantages, still they did not
become the main-stream system...yet.
Michael, I found your part very interesting dealing with different
types of speakers. Could you post some information please where to find
info about these special types of speakers?
All the best,
Jan Jacob
sound | movement | object |
space
sonic architecture | site: http://www.sonicarchitecture.de
spatial electronic composition | 2nd order ambisonic music
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