Are you still here by any chance. I'm learning audio circuit as a side hobby for my guitar. I know a lot relative to someone with zero official education(well, you don't have to have an official education to know far more than I. The point, I'm trying to figure what I'm missing that would allow me to understand why this circuit behavior is observed. Say you have an input audio signal going to the first lug of a pot, a capacitor with a Resistor that's about 1/3rd the Pot value bridging across lug 1 & 2, lug two connecting to audio out. Lug 3 to a Resistor about 1/8th of the Pot value then to ground. What I'm trying to figure out is why does this circuit merely pass a fixed cutoff as opposed to adjusting the resistance = adjusting the cut-off frequency?