[sdiy] Thoughts on drum synth

[Tim Ressel]

Christian,

> Fascinating...
> is this EVERY drum with a circular head?  I'm
> assuming this is for a head
> stretched to a specific tension all the way
> around... or does the tension of
> the different parts of the drum just change the
> relationship of the mode
> amplitudes to the fundamental?

Assumes equal tension across the head.
Formula for freq of stretched membrane:

Fo = (0.382/R) * sqrt(T/m)

R=Radius of membrane in centimeters
T=tension in dynes per centimeter
m=mass of membrane in grams per square centimeter


> this would be interesting.  Modeling this seems
> intriging... I've been
> studying physical modeling for a while and wonder if
> we this could me
> modeled with a delay line representing the 'height'
> of the drum with a
> scattering junction at end.  Sort of like a Physical
> model for a horn or
> flute, but with a really different excitation
> signal...

Because the radius is much larger than the length, the
end effects kinda swamp the tube effect. That's why I
said the filter would have a low Q. Physical modelling
would be fun, if a bit overkill...


> oh, and the Walsh thing looks super cool.  I was
> thinking of trying to do
> this on my DSP too.

I'm still confused over how one would do this. And i'm
wondering why one would do this, when Fourier
synthesis is so much more simple.

--tr


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