Remove hum when recording sounds

To remove the mains electricity hum when recording with Snooper, you can apply a pre-recording filter. The hum is usually present at frequency 50 Hz or 60 Hz so a high-pass filter or a notch filter should be fine.

Removing the hum would significantly improve the quality of the recording and make triggering more accurate.

Measuring the frequency distribution with the built-in frequency analyzer with no filter shows:

Frequency analyzer – no filter

Set the filter to a high-pass filter with a cutoff-frequency of 200 Hz.


This will attenuate the hum at 50 Hz and the harmonic at 100 Hz with approximately 20 dB.

Frequency analyzer – high-pass 200Hz


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