I found this on Ethans site…

// Analog Transfer Function: H(s) = s^2 / (s^2 + s/Q + 1)

float Fs = 44100;

float Pi = 3.141592;

float f0 = 100; //cut-off

float Q = 1.5; //filter Q

float w0 = 2 * Pi * f0 / Fs;

float alpha = sin(w0) / (2 * Q);

float a0 = 1 + alpha;

float a1 = -2 * cos(w0);

float a2 = 1 - alpha;

float b0 = (1 + cos(w0)) / 2;

float b1 = -(1 + cos(w0));

float b2 = (1 + cos(w0)) / 2;

float Buffer[1024];

float PrevSample[3]; //max3

int I = 0;

int N = 1024;

while (I < N) {

PrevSample[2] = PrevSample[1]; //slide sample position

PrevSample[1] = PrevSample[0];

PrevSample[0] = Buffer[I];

Buffer[I] = ( b0 / a0 * PrevSample[0]) +

(b1 / a0 * PrevSample[1]) +

(b2 / a0 * PrevSample[2]) -

(a1 / a0 * Buffer[I - 1]) -

(a2 / a0 * Buffer[I - 2]);

I = I + 1;

}

I know that’s probably way basic, but what am I looking at? Is this en entire EQ plugin or just a single band? Can anyone tell by looking at it?