If a 1st order Butterworth filter has a minus 3db point at 140Hz and a minus 9db point one octave lower at 70Hz how does one calculate the minus 6db point?
Presumably this will be around 100Hz? Is there a formula?
Forever mathematically challenged but trying.. 🙂
Presumably this will be around 100Hz? Is there a formula?
Forever mathematically challenged but trying.. 🙂
A(dB) = 10 log[1+(wx/wc)^2n]
A =attenuation at wx;
wx/wc is ratio of freq where att is wanted to 3dB filter cutoff freq wc;
n = filter order
Jan Didden
A =attenuation at wx;
wx/wc is ratio of freq where att is wanted to 3dB filter cutoff freq wc;
n = filter order
Jan Didden
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