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wgpluck

A high fidelity simulation of a plucked string, using interpolating delay-lines.

Syntax

ares wgpluck icps, iamp, kpick, iplk, idamp, ifilt, axcite

Initialization

icps -- frequency of plucked string

iamp -- amplitude of string pluck

iplk -- point along the string, where it is plucked, in the range of 0 to 1. 0 = no pluck

idamp -- damping of the note. This controls the overall decay of the string. The greater the value of idamp, the faster the decay. Negative values will cause an increase in output over time.

ifilt -- control the attenuation of the filter at the bridge. Higher values cause the higher harmonics to decay faster.

Performance

kpick -- proportion of the way along the point to sample the output.

axcite -- a signal which excites the string.

A string of frequency icps is plucked with amplitude iamp at point iplk. The decay of the virtual string is controlled by idamp and ifilt which simulate the bridge. The oscillation is sampled at the point kpick, and excited by the signal axcite.

Examples

Here is an example of the wgpluck opcode. It uses the file wgpluck.csd.

An example of the wgpluck opcode.
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<CsoundSynthesizer>
<CsOptions>
; Select audio/midi flags here according to platform
; Audio out   Audio in
-odac             ;;;RT audio out
; For Non-realtime ouput leave only the line below:
; -o wgpluck.wav -W ;;; for file output any platform
</CsOptions>
<CsInstruments>

; by Menno Knevel 2021

sr = 44100
ksmps = 32
nchnls = 2
0dbfs  = 1

instr 1

icps = 220
iamp = 1
kpick = 0.5
iplk = 0
idamp = p4
ifilt = p5
ichoice = p6

if ichoice == 1 then
    axcite =    0                   ; no exciter signal
else
    axcite diskin2  "fox.wav", 1    ; use the fox as exciter
    axcite *=   .15                 ; but lower amplitude
endif

apluck wgpluck icps, iamp, kpick, iplk, idamp, ifilt, axcite
apluck  dcblock2    apluck          ; gets rid of DC offset
outs apluck, apluck

endin

</CsInstruments>
<CsScore>
f 1 0 16384 10 1        ; sine wave.
s
;          damp     filter  choice           
i 1 0 8     10      1000      1
i 1 + 8     30      10        1
s
i 1 0 8     10      1000      2
i 1 + 8     30      10        2
e
</CsScore>
</CsoundSynthesizer>

See also

Waveguide Physical Modeling

Credits

Author: Michael A. Casey
M.I.T.
Cambridge, Mass.
1997

New in Version 3.47