Figure 15:
The Karplus-Strong plucked string block diagram.
The KS algorithm (shown again in Fig. 15) can be viewed as a feedback comb filter with an embedded lowpass filter (referred to as a lowpass-feedback comb filter). Interestingly, this structure is commonly used in room reverberation algorithms.
The fact that this algorithm produces the sound of a plucked string can be understood from the resonant pattern of the feedback comb filter, together with the lowpass filter (which causes the resonance gains to decrease at higher frequencies), together with the initial wideband excitation.
In an article published at the same time as (Karplus and Strong, 1983), Jaffe and Smith (1983) hinted that the Karplus-Strong algorithm could be viewed as a model of traveling-wave motion on a string.
The following sections on Digital Waveguide Modeling provide further details on that interpretation.
