protected override void CalcBiquad() { double norm; norm = 1d / ( 1 + _K / _Q + _KSq ); _a0 = _K / _Q * norm; _a1 = 0; _a2 = -_a0; _b1 = 2 * ( _KSq - 1 ) * norm; _b2 = ( 1 - _K / _Q + _KSq ) * norm; }