Hi, I'm looking to implement a 3rd order Butterworth LowPass and HighPass. I understand that in order to get a 3rd order filter I need to cascade a 2nd order with a 1st order. A Q-factor look-up table can be found in this datasheet p58. http://focus.ti.com/lit/ml/sloa088/sloa088.pdf KX currently only implements a 2nd order filters. I found the formulas to compute the biquad coefficients for 1st order filters. Cascade form IIR Filters | Comp.DSP | DSPRelated.com I've been trying to compute and replace these coefficients into the "EQ Lowpass" filter but I can't get it to work. Does what I'm trying to do seem right? I don't quite understand how the "EQ Lowpass" biquad implementation uses the coefficients and I have some questions. - Are all of the coefficients divided by 2? - From the EQ-Cookbook a0 = 1 + alpha doesn't come up to 1, does that mean that the rest of the coefficients must be offset by -alpha? - Can I type decimal fractions into the Dane editor or do I need to convert to hex?