If I have a BiQuad all-pass filter with a given set of coefficients such as:
g: 0.903228 a1: -1.88142 a2: 0.903228 B1: -2.08299 B2: 1.10714
And my operation per sample to process the filter is:
inputGained_2 = inputGained_1; inputGained_1 = inputGained; inputGained = input * g; output_2 = output_1; output_1 = output; output = inputGained + (B1 * inputGained_1) + (B2 * inputGained_2) - (a1 * output_1) - (a2 * output_2); return output;
And this is running at 44.1 kHz: What equation could I used to calculate the group delay at a given frequency like say 82 hz?