[music-dsp] Zoelzer/RBJ biquad code in archives

[Chris Townsend]

I'll try beating Robert to the punch on this.  Have you read Robert's
article about "The Equivalence of Various Methods of Computing Biquad
Coefficients for Audio Parametric Equalizers"?  It might help answer your
question.

-chris

http://www.harmony-central.com/Effects/Articles/EQ_Coefficients/EQ-Coefficie
nts.pdf


----- Original Message -----
From: "Citizen Chunk" <citizenchunk at nyc.rr.com>
To: "a list for musical digital signal processing"
<music-dsp at shoko.calarts.edu>
Sent: Sunday, March 28, 2004 9:35 PM
Subject: [music-dsp] Zoelzer/RBJ biquad code in archives


> i've been playing around with the various filter algos in the
> musicdsp.org archives--great stuff! the RBJ filters look cool, as do
> the Zoelzer biquads. i couldn't help noticing that they're basically
> the same filters (when you plot them)--the RBJ text gives a transform
> that was probably used to adjust the variables. it also seems to me
> that the Zoelzer might be a little more efficient. (eh?)
>
> unfortunately, it doesn't quite make sense to me how the reduction
> works (it's been a while since i dealt with sin & cos relationships),
> so i couldn't map the RBJ HPF coefficients to the Zoelzer variables.
> does anyone know what the Zoelzer HPF coefficients would be?
>
> thanks again to the group for all the awesome advice.
>
> == chunk
>
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