Hack Audio: High-Pass Filter

Another type of spectral effect is the high-pass filter. This effect reduces the amplitude of low frequencies while letting high frequencies pass through unattenuated. The HPF can be created in a similar way to the LPF, with one important difference. On the parallel delay path, the signal is flipped by a gain of negative 1. This switches which frequencies have constructive interference and destructive interference. This tutorial demonstrates how to implement the effect in Matlab and how to analyze the frequency response. Check out http://www.hackaudio.com/ for more information.