lowresx

Simulates layers of serially connected resonant lowpass filters.

Syntax

ares lowresx asig, xcutoff, xresonance [, inumlayer] [, iskip]

Initialization

inumlayer -- number of elements in a lowresx stack. Default value is 4. There is no maximum.

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

lowresx is equivalent to more layer of lowres with the same arguments serially connected. Using a stack of a larger number of filters allows a sharper cutoff. This is faster than using a larger number of instances of lowres in a Csound orchestra because only one initialization and k cycle are needed at time and the audio loop falls entirely inside the cache memory of processor. Based on an orchestra by Hans Mikelson

Examples

Here is an example of the lowresx opcode. It uses the file lowresx.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 lowresx.wav -W ;;; for file output any platform
</CsOptions>
<CsInstruments>

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

instr 1

kres = p4
inumlayer = 4

kenv linseg 0, p3*.1, 1, p3*.8, 1, p3*.1, 0     ;envelope
asig vco .3 * kenv, 220, 1                      ;sawtooth
kcut line 30, p3, 1000                          ;note: kcut is not in Hz
alx  lowresx asig, kcut, kres, inumlayer        ;note: kres is not in dB
aout balance alx, asig                          ;avoid very loud sounds
     outs aout, aout

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

i 1 0 5 1
i 1 + 5 3
i 1 + 5 20
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

Audio rate parameters introduced in version 6.02

November 2013.