When you want to get the specific frequency (ex. around 1000Hz), you might
- take FFT, remain the frequency you want, and reduce the power of the other frequencies you do not. ex.) if fs=16khz and fftsize=1024, remain the power of bin64 and reduce all other bins
- design band pass filtering (Butterworth or others) to pass 1000Hz (with stop/transition band also)
In short, 1 is in frequency domain, and 2 is in time domain.
Then my question is: are these two methods same? (I think yes in terms of "extracting 1000Hz signal"(Both can do)) If yes, how would you utilize these two methods? If not, how different are these (and how would you utilize)? I would appreciate your answers. Thank you.