How can I remove harmonics from my spectrogram?

There are several harmonics plotting in my power spectral density spectrogram but I only want to include the first one. How can I remove the other harmonics?

Answer 1

[Star Strider]

If you know the frequency of the fundamental (that is what I assume you are referring to), use the bandpass function on the time-comain signal. For best results, specify the name-value pair 'ImpulseResponse','iir'.