ABSTRACT
If that is as clear as mud, don’t panic. As I said in the preface, this book attempts to avoid getting involved in the whole complex algebra business. For our purposes, a pole causes the frequency response to turn downwards by 6 dB per octave, as in a simple first-order RC lowpass filter. A zero causes the frequency response to turn upwards by 6 dB per octave, but it is not equivalent to a first-order CR highpass filter; that is represented by the combination of a pole and a zero. You can see why this stuff is hard to understand.
