Controlling Karplus-Strong

Controlling Dynamics:

• Limit the range of random numbers--change the Matlab line

  xn = 2*(x-0.5); % uniform between -1 and 1
  

• Filter the white noise serving as the initial conditions. The cut-off frequency of the filter will control the effective dynamic level (since acoustic instruments are usually brighter at louder dynamic levels).

Sounding frequency (pitch)

• Change the delay line length, where
  $$f_0 = f_s/(N+1/2).$$

• The $1/2$ term in the denominator is due to the low-pass filter's phase delay of 1/2 sample.

• Notice that the delay-line length is of an integer size. This limits the resolution of possible sounding frequencies.