Reply by Vladimir Vassilevsky●April 28, 20102010-04-28
SYL wrote:
> Hi all,
>
> Just found this piece of code from my old collection. But could not
> find where it came from? Can anyone shed some light? I know it is from
> butterworth and bilinear transform. But seemed not quite that,
> particularlly the resonanceDB to r part.
>
> -----------------------------------------------
> c = 1.0 / (tan(pi * (fc / fs)));
> csq = c * c;
> r = 10.0^(-(resonancedB * 0.1));
> q = sqrt(2.0) * r;
> a0 = 1.0 / (1.0 + (q * c) + (csq));
> a1 = 2.0 * a0;
> a2 = a0;
> b1 = (2.0 * a0) * (1.0 - csq);
> b2 = a0 * (1.0 - (q * c) + csq);
> -----------------------------------------------
Hi all,
Just found this piece of code from my old collection. But could not
find where it came from? Can anyone shed some light? I know it is from
butterworth and bilinear transform. But seemed not quite that,
particularlly the resonanceDB to r part.
-----------------------------------------------
c = 1.0 / (tan(pi * (fc / fs)));
csq = c * c;
r = 10.0^(-(resonancedB * 0.1));
q = sqrt(2.0) * r;
a0 = 1.0 / (1.0 + (q * c) + (csq));
a1 = 2.0 * a0;
a2 = a0;
b1 = (2.0 * a0) * (1.0 - csq);
b2 = a0 * (1.0 - (q * c) + csq);
-----------------------------------------------
Thanks