Thanks for the info.

For the record,
I'm trying to measure the response of the whole system, including
microphone, room and speakers. When doing live sampling of audience at
a sound installation, I would like to try to enhance transient
detection by suppressing the sounds that Csound sends into the room. I
do not need exact phase, as I don't try to "phase out" my own output,
I will only trace the amp contour of my own output and subtract that
from the amp contour of the signal coming into the microphone.
I've got something that kind of works, but need to get the frequency
response of the system right, as this obviously affects the amp
contour significantly.

Oeyvind

2008/6/4, victor <Victor.Lazzarini@nuim.ie>:
> I suppose you need to apply deconvolution to get
> the impulse. Fons Adriaensen <fons@kokkinizita.net>
> is your man  to give the exact details (I have
> not done that myself yet). He's got a software for
> IR measurement.
>
> Victor
>
>
> ----- Original Message ----- From: "Oeyvind Brandtsegg" <obrandts@gmail.com>
> To: <csound@lists.bath.ac.uk>
> Sent: Wednesday, June 04, 2008 11:56 AM
> Subject: [Csnd] Re: Re: pvsmaska
>
>
>
> > Ah, you're right. Thanks. I did not think of that.
> >
> > As for the sine sweep method of recording an impulse response,
> > how do I post process the recording of the sine sweep to leave only
> > the "response" and get rid of the original sine sweep ?
> > Could I just subtract a delayed version of the sine sweep to phase out
> > the original signal in the response recording ?
> >
> > best
> > Oeyvind
> >
> > 2008/6/3, Victor Lazzarini <Victor.Lazzarini@nuim.ie>:
> >
> > > Oeyvind,
> > >
> > > 1. instead of using pvsmaska, you could try pvsfilter
> > > that does the same thing but with two fsigs. Note that
> > > both pvsmaska & pvsfilter will not affect the phase
> > > of the signals, so the transformation is magnitude-only.
> > >
> > > 2. I would have thought you could record the impulse
> > > response of your system and then use pconv to
> > > process the audio. That will use mag+phases
> > > (full-featured convolution).
> > >
> > > Regards
> > >
> > > Victor
> > >
> > >
> > > At 10:24 03/06/2008, you wrote:
> > > >
> > > > Hi
> > > >
> > > > I'm trying to write an instrument that will analyze the frequency
> > > > response of my audio system (the signal path from Csound output, via
> > > > speakers, microphone, and back into Csound).
> > > >
> > > > I want to use the result of the analysis to shape an audio signal (all
> > > > inside Csound) so that it will sound (as close as possible) like it
> > > > has been played through the speakers and recorded back into Csound.
> > > >
> > > > I figured I could use the pvs opcodes, with pvsftw writing a table
> > > > with amplitudes for all frequency bands in the analyzed signal (audio
> > > > system response simulated with an arbitrary filter in the attached
> > > > csd), then use pvsmaska to shape the frequency response of another
> > > > signal.
> > > >
> > > > This works in terms of frequency response, but the overall amplitude
> > > > is very low for the "shaped" signal (aout in instr 2 of the attached
> > > > csd).
> > > > I wonder if there are some formula for gain makeup in this case ?
> > > > It seems to me in theory this should just work "out of the box), with
> > > > no need for makeup gain, or am I way off in supposing it should work ?
> > > >
> > > > best
> > > > Oeyvind
> > > >
> > > > Send bugs reports to this list.
> > > > To unsubscribe, send email sympa@lists.bath.ac.uk with body >
> "unsubscribe
> > > csound"Content-Type: application/octet-stream;
> name=auto_calibrate_pvs2.csd
> > > > X-Attachment-Id: f_fh0a9i9o
> > > > Content-Disposition: attachment;
> > > filename=auto_calibrate_pvs2.csd
> > > >
> > >
> > > Victor Lazzarini
> > > Music Technology Laboratory
> > > Music Department
> > > National University of Ireland, Maynooth
> > >
> > >
> > >
> > >
> > > Send bugs reports to this list.
> > > To unsubscribe, send email sympa@lists.bath.ac.uk with body "unsubscribe
> > > csound"
> > >
> > >
> >
> >
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> >
>
>
>
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