It's a good read, but it highlights to me the fact that you really need to understand the compact maths that describes all this (in this case the Fourier transf

It's a good read, but it highlights to me the fact that you really need to understand the compact maths that describes all this (in this case the Fourier transform) at which point it's all rather simple. I notice that much of signal processing discussion at the hardware level involves lots of hand waving and attempts to avoid even complex numbers.