Hello Csounders, I am relatively new in Csound and in the list, I am trying to equalize a soundfile using butterbp and butterbr but I don't understand how it functions because butterbp seems to work good enought but butterbr seems to work but do nothing,compiling I don't have any error but I can't hear any difference between the  unprocessed and the processed soundfile.
Anyone can explain me what I am doing wrong?
Thanks.

;--------------Equalizer.orc ------------------------------------

sr= 44100
kr=4410
ksmps= 10
nchnls=1

instr 1

idur=p3
iamp=p4
iskiptime=p5
iattack=p6
irelease=p7
ifile=p8
icf1= p9
ibw1=p10
icf2= p11
ibw2= p12

asig1 soundin p8,p5 

;afilt01 butterbr asig1,icf1,ibw1 ;butterbp works fine
;afilt02 butterbr asig1,icf2,ibw2

afilt01 butterbr asig1,icf1,ibw1  ;butterbr don.t seems to work
afilt02 butterbr asig1,icf2,ibw2

afilt1b balance afilt01,asig1
afilt2b balance afilt02,asig1

afilters=(afilt1b+afilt2b)/2

out afilters
endin

;---------------------- Equalizer.sco ----------------------------

; instr( p1 )  start( p2 )  dur( p3 )  amp( p4 ) skip( p5 ) atk( p6 ) 
   i1           0           20          1        0         .03       
;rel( p7 ) ifile( p8 )  centerfreq1( p9 ) bandwidth1( p10 ) centerfreq2( p11 ) 
  .1          0              1000               100             2000
;bandwidth2 ( p12 ) 
   100
e

Marc Sola
msola@phonos.upf.es
http://phonos.upf.es/~msola

At 5:41 PM +0000 11/18/97, Marc Sola Subirats wrote:
>butterbr seems to work but do nothing,compiling I don't have any error but
>I can't hear any difference between the  unprocessed and the processed
>soundfile.
>Anyone can explain me what I am doing wrong?

Band block filters are extremely subtle in their audible effect. I just did
a demo this morning to a signal processing class. Highpass, Lowpass, and
Bandpass are easy to hear but Bandreject is very difficult. Try the
folloing .orc and .sco:

ORC:
sr = 44100
kr = 44100
ksmps = 1
nchnls = 1

      instr 1
kfreq expseg 5*p4,p3/2,0.9*p4,p3/2,5*p4
a1 oscil  20000, p4, 1
a2 butterbr  a1, kfreq, kfreq/5
      out a2
      endin

SCO:
f1 0 16384 10 1 1 1 1
i1 0 30 220

There are only four harmonics so you should be able to hear as each one is
blocked out. Even here it is subtle unless you're very used to listening to
individual harmonics.


-------------------------------------------------------------------------------
Erik Spjut (rhymes with cute) - Acting Director,The Center for Design Education
and/or Associate Professor of Engineering
Harvey Mudd College, Claremont, CA 91711  USA
Erik_Spjut@hmc.edu      Ph & Voice mail (909) 607-3890      Fax (909) 621-8967