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 | | From: | CoastalMaineBird | | Subject: | Re: Generate signal using transfer function | | Date: | Wed, 19 Jan 2005 14:40:13 -0600 (CST) |
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 | Don't use the Transfer function itself. Take a look at what it's doing.>If you open it up, you'll see it basically divides the spectrum of the res=
ponse by the spectrum of the stimulus. The rest is housekeeping to make dis=
play easier.
So: Xfer =3D Response / Stimulus (In freq. domain).
=
If want a given response, turn that equation around and adjust your sti=
mulus:
Response =3D Stimulus * Xfer.
In other words, take your st=
imulus signal, and get it's spectrum.
Multiply that spectrum by the Xf=
er function, and convert back to the time domain, before output to the ampl=
ifier.
Keep in mind that your Xfer function is the SYSTEM xfer funct=
ion, meaning that it measures the xfer function of the whole system (D/A co=
nverter, amplifier, speakers, room acoustics, microphone, preamp, A/D conve=
rter).
If you want to output a sine wave, you could generate the spe=
ctrum directly, without generating a sine wave and taking it's spectrum, bu=
t that's another question...
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