[PD] Pre Loading a Delay Line

'Frank Barknecht' fbar at footils.org
Fri Dec 8 18:56:44 CET 2006


Hallo,
Michael Garrett hat gesagt: // Michael Garrett wrote:

> Thanks for all the great conversation!!!
> 
> First thing, now that I have done some research, I am getting KS, and
> Waveguide synthesis confused. What I have patched up is a Karplus Strong
> synth, that sounds like a PVC pipe... It is not really a waveguide synth in
> the true sense. The initial noise burst, which comes through, is desirable
> in this synth, since it represents the percussive hit of the pipe end.
> 
> One thing about pre loading the delay line, is getting the true sound of the
> recalculating line itself, without the noise pulse at the beginning. You can
> output the delayed signal, but it appears 20 msec or so 'late' for bass
> notes.
> 
> I picture it similar to pulling a bass string with your finger, you are
> adding energy to the string, but there is no sound from adding this energy.
> So the string, in cross section looks like a single cycle of a saw tooth.
> The pickup is located someplace on the string, and starts producing sound
> the instant the string is released, not 20 msec later, the timbre of the
> sound based on the energy stored by the finger being released.

But isn't it like this: Even there, the travelling wave will only be
heard once it was reflected at the end of the string and reaches the
pickup again. What you hear before that moment is the "impulse"
created by letting go of the string. 

As I see it, the only difference between the original impulse and the
first delayed impulse that you hear from the [vd~] 20ms later is that
the delayed impulse is filtered by the [vcf~]. You could filter the
initial impulse at the pickup-[outlet~] in the same way if you want
to. 

Ciao
-- 
 Frank Barknecht                 _ ______footils.org_ __goto10.org__




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