I need to construct an RC high pass filter to remove anything below 200hz.
This will be used for recording birdsong form a panasonic electret mic.
I can see how to make the very simple circuit but how do you calcultate the best value for the resistor and capacitor to avoid signal loss as much as possible?
One capacitor feeding one resistor makes a poor filter because it is single-order with a gradual slope. When its cutoff frequency is 200Hz which will be reduced to -3dB then 100Hz is at -6dB, 50Hz is at -12dB and 25Hz is at -18dB are stll fairly loud. A second-order Sallen and Key Butterworth filter using an opamp is twice as good. A third-order Sallen and Key Butterworth filter is even better.
High Pass Filter Components?
Posted - Apr 01 2011 : 2:08:52 PM
