Designing Audio Effect Plugins in C++, 2nd Edition

Chapter 9How DSP Filters Work (Without Complex Math)

DSP filter theory involves complex algebra, that is, the algebra of complex numbers that involve the $\sqrt{\text{-1}}$. Complex numbers contain real and imaginary parts. Rather than simply throw a bunch of equations and algebra at you, I prefer to ease into the theory by starting with a method of examining, stimulating, and testing a DSP filter without complicated math. We may also predict its frequency and phase responses from the data we collect in the process. This method will only require some tabulated bookkeeping. The way you shuffle audio samples through the tables is going to ultimately correspond to C++ code that you will eventually need to write, making that process easier to understand. We’ve traded ...