This sound is a bit comparable to the Kyma HarmonicResonator. Instead of having only one delay line, this prototype has two. This enables full stereo operation, but also cross feeding. The feedback contains a 1st order recursive low pass filter and not (as in many implementation of Karplus Strong) an averager or FIR filter. The Resonator is setup to output the original always and only in the feedback loop are the delays and the low pass filter. To simulate different plucking or pickup positions one can mix a delayed version of the input signal. This gives notching effects.
Since the microsound implementation contains two delays with feedback and cross feedbacks from one to the other and visa versa, it is very easy to get it to self oscillate (this is not nice!). I decided to go for four configurations: a,b,c and d in which the self oscillation is hidden for you. It took a long time to invent interesting formulas for these values.
In the a and b configuration I assumed the input to be real numbered stereo audio signals. In the c and d configuration I assumed the input to be complex numbered audio signals.
-- ChristiaanGelauff - 23 Feb 2007 Back one page
A screenshot for Resonator1a:
A screenshot for Resonator1d: