[CM] translating spirals into music CLM

[john henry dale]

hi fernando,
I am getting repetitive clicking noises from the speakers when I put the
following code into CLM using a 4 speaker arrangement. The sample file is
mono.

(with-sound (:channels 4 :Scaled-to .99 :Srate 44100 :statistics t
             :reverb nrev :Printing nil)
     (move-it (:channels 2
            :paths (list (make-path '((-10 10)(0.1 0.1)(10 -10)))
                         (make-spiral-path :turns 2)))

       (samp2 "eastern_guitar.aif" 0)))

i am also getting these type of warnings:

"WARNING:
   supersonic radial movement at [2.3851562,-2.2046876,0.0, 0.61474013],
speed=28.252476"

The sound spirals around the speakers nicely, except for the clicks.
What am I doing wrong here ?

Thanks,
JHD




On 8/2/07, Fernando Lopez-Lezcano <nando at ccrma.stanford.edu> wrote:
>
> On Wed, 2007-08-01 at 23:49 +0100, john henry dale wrote:
> > Hi Fernando,
> > in taking a look at dlocsig.html, I found what seems to be a way to
> > generate spiralling sound spatialization using Geometric Paths
> > (dlocsig.html#geometric-paths):
> > make-spiral-path
> > &optional-key
> >
> >
> > (start-angle 0d0)
> > (total-angle nil)
> > (step-angle (/ dlocsig-one-turn
> > 100))
> > (turns nil)
> > (distance '(0 10 1 10))
> > (height '(0 0 1 0))
> > (velocity '(0 1 1 1))
> >
> > But i'm not sure where in my CLM composition's code I would insert
> > this spiral path info to actually apply this spatialization to my
> > output track.
> > For my performance the audience will be surrounded by 9 speakers ( 4
> > on the floor, 4 at slightly above ear level when sitting + one speaker
> > above) , so basically a cube of about 25x 25 x 5 feet  with a speaker
> > at each corner and a tweeter tree overhead. I'm trying to figure out
> > two things in this email:
> >
> >
> > 1) What arguments do i give the make-spiral-path function to generate
> > a logarithmic spiral which goes upward into a cone which would come to
> > its apex at the height of the audience's ears (about 5 feet 5 inches)
> > with a total angle of 23.5 degrees ?
>
> You can (should) be able to use "distance" and "height" to do what you
> need to. "distance" is the distance between the listener and the moving
> object - it can be a 3d list provided that path-3d is "t", such as '(0 1
> 0)(0 2 3)), etc, where each sublist is an x/y/z triple. Same for
> height.
>
> > Basically i am trying to mimic the spiral created by the Earth's
> > precessional cycle on a small scale for my final performance. This
> > might be easier with a visual aid. Check this movie out:
> > http://www.lunarplanner.com/HCmovies/HCmovie300Frame.html. So using
> > this movie as a model, the height of the spiral at its apex (and at
> > the climax point of the composition) would be, figuratively, in the
> > center of the earth where the two cones formed by earth's 23.5 degree
> > wobble on its axis come together at one point. Does that make sense ?
> >
> >
> > 2) What arguments do I give the arrange-speaker functions to, i.e. how
> > would I map this speaker arrangement ?
>
> I think this is still valid, there's some details there (and I think
> there's a dlocsig.html file in the clm distro as well):
>
>   http://ccrma.stanford.edu/~nando/clm/dlocsig/
>
> Basically you specify angles (azimut and elevation) for the speakers and
> then you have to group them in triads for 3d (ie: you have to
> tesselate(sp?) space so that it is covered with three adjacent speaker
> groups - I gave up on finding lisp code that would do that
> automatically). There are some default configurations in the source file
> that should provide a guide.
>
> > What were your results in testing these spiral paths on a
> > multi-speaker system ? Did you use gnuplot to generate your spiral
> > coordinates or can you fairly easily plug them into the
> > make-spiral-path argument ?
>
> They sounded, well, like spiral paths :-) That does not necessarily mean
> they make good musical sense, of course... Sometimes I did use gnuplot
> to visualize them, there's some functions in the code to drive gnuplot
> but I have not tested the whole thing in a long time, I don't know if
> all that code still works.
>
> >  Also,  would i also need to render my final output as an Ambisonics
> > file for 9 speakers to accomplish something like this ?
>
> You choose your rendering model. No need to use Ambisonics. The
> advantage of it being that you could render to an Ambisonics B format 4
> channel soundfile and then decode that at "listening time" for any array
> of speakers with the proper decoder.
>
> > Sorry for the heavy question-load, but I'm getting a little lost in
> > all this 3-d spatialization stuff.
>
> It is complicated...
> -- Fernando
>
>
>
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