Profile photo of mervaka

Thinking about it, a dedicated fourth order LPF/HPF would actually require the same number of coefficients (and therefore multiplications and additions/subtractions) as a biquadratic filter, so 3rd and 4th order filters could be implemented without additional DSP processing cost if dedicated HPF/LPF algorithms were implemented for each filter order. However, extra unit delays are used, so an additional 50%/100% extra data memory would be required for each filter.