Second-order TransferFunction works in the wrong direction

[onguntoglu]

Second-order TransferFunction works in the opposite direction, needs tests and math check

[onguntoglu]

Two different ways to calculate the coefficients seem to deliver the same result, meaning the math is OK

[onguntoglu]

Hmm, no, two different calculation method do not return the same values, some values are actually halved. Coefficient calculation must have been faulty, needs check