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: