I need to retrieve the biquad coefficients starting from (freq, gain Q) triplets, exactly as the [filtergraph~] object does. I managed either to google or to work out the maths for all the types of filters (bandpass, peaks, shelves), except for resonant and allpass filters.

Would it be possible for you to share how the coefficients are obtained from the (freq, gain, Q) information?

Thanks,

Daniele

Thanks again,

Daniele