lowres

Another resonant lowpass filter.

Syntax

ares lowres asig, xcutoff, xresonance [, iskip]

Initialization

iskip -- initial disposition of internal data space. A zero value will clear the space; a non-zero value will allow previous information to remain. The default value is 0.

Performance

asig -- input signal

xcutoff -- filter cutoff frequency point

xresonance -- resonance amount

lowres is a resonant lowpass filter derived from a Hans Mikelson orchestra. This implementation is much faster than implementing it in Csound language, and it allows kr lower than sr. xcutoff is not in Hz and xresonance is not in dB, so experiment for the finding best results.

Examples

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

<CsoundSynthesizer>
<CsOptions>
; Select audio/midi flags here according to platform
-odac     ;;;realtime audio out
;-iadc    ;;;uncomment -iadc if realtime audio input is needed too
; For Non-realtime ouput leave only the line below:
; -o lowres.wav -W ;;; for file output any platform
</CsOptions>
<CsInstruments>

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

instr 1

kres = p4
asig vco .2, 220, 1             ;sawtooth

kcut line 1000, p3, 10          ;note: kcut is not in Hz
as   lowres asig, kcut, kres    ;note: kres is not in dB
aout balance as, asig           ;avoid very loud sounds
     outs aout, aout

endin
</CsInstruments>
<CsScore>
; a sine
f 1 0 16384 10 1

i 1 0 4 3
i 1 + 4 30
i 1 + 4 60
e
</CsScore>
</CsoundSynthesizer>

See also

Standard Filters: Resonant Low-pass filters

Credits

Author: Gabriel Maldonado (adapted by John ffitch)
Italy

New in Csound version 3.49