mvclpf4 — Moog voltage-controlled lowpass filter emulation.
Mvclpf4 is an digital implementation of the 4th-order (24 dB/oct) Moog ladder filter originally written by Fons Andriaensen. It is a version of the mvclpf3 opcode with four outputs, for 6dB, 12dB, 18dB, and 24 dB/octave responses.
istor --initial disposition of internal data space. Since filtering incorporates a feedback loop of previous output, the initial status of the storage space used is significant. A zero value will clear the space; a non-zero value will allow previous information to remain. The default value is 0.
asig1 -- 6dB/oct low-pass response output.
asig2 -- 12dB/oct low-pass response output.
asig3 -- 18dB/oct low-pass response output..
asig4 -- 24dB/oct low-pass response output.
ain -- input signal.
xcf -- filter cutoff frequency. The useful range is around six octaves below and above middle C (pch 8.00).
xres -- resonance, limited to the interval [0,1].
Here is an example of the mvclpf4 opcode. It uses the file mvclpf4.csd.
Example 648. Example of the mvclpf4 opcode.
See the sections Real-time Audio and Command Line Flags for more information on using command line flags.
<CsoundSynthesizer> <CsOptions> -odac </CsOptions> <CsInstruments> 0dbfs = 1 instr 1 asig[] init 4 kenv linen p4,0.1,p3,0.1 ain rand kenv kfr expon 220, p3, 1760 asig[0],asig[1],asig[2],asig[3] mvclpf4 ain,kfr,0.9 out asig[p5] endin </CsInstruments> <CsScore> i1 0 5 0.9 0 i1 + 5 0.9 1 i1 + 5 0.9 2 i1 + 5 0.9 3 </CsScore> </CsoundSynthesizer>