41 Replies Latest reply on Mar 14, 2020 5:03 PM by shabaz

    Trying to understand how R & C affect an audio signal when used in a high pass filter


      Hi all,


      I am looking at creating a simple high pass filter for a microphone breakout board which will be attached to a MCU.


      I'm not an electronics engineer so this is probably a simple 101 type question for those who are.


      I've learnt from Wikipedia that the formula for determining the cut off frequency is:



      and that R x C is the time constant.


      Now what I am trying to learn is how else does R and C impact the audio signal as this presents me with 2 degrees of freedom.


      For example if I went with a 100 ohm resistor and say used a 1 uF capacitor, how does this compare with a 100k Ohm resistor and a 1 nF capacitor as both these options give me the same fc.


      I'm assuming it must impact that ramp up curve but not sure how (image source Wikipedia).



      Hence the question to the community experts.


      The circuit I'm using is as follows: