How to reduce 50 Hz hum in a video while watching

A steady low buzz often comes from mains electricity, power supplies, grounding or the recording equipment.

Distinguish hum from hiss

Electrical hum often sounds like a steady low tone that continues through pauses and barely changes with speech. Hiss is a broader background without one clear note. Both can occur in the same recording.

Listening alone cannot reliably identify the exact frequency or cause. Power and recording equipment can introduce hum, but ventilation and other sources can sound similar. Test the 50 Hz filter rather than enabling it for every video.

What noise filters

“Remove 50 Hz hum” reduces the fundamental frequency and its harmonics: 100, 150 Hz and onward up to 500 Hz. Harmonics are multiples of the fundamental and can make a low hum sound like a more noticeable buzz.

This control is separate from RNNoise and GTCRN. It targets specific frequencies and does not replace broadband noise reduction.

Test the filter on your recording

1. Find a pause followed by a few words from a low voice.
2. Enable cleaning. Initially keep noise reduction and speech leveling at zero and the equalizer neutral.
3. Enable “Remove 50 Hz hum” and listen to the pause. Is the unwanted tone quieter?
4. Check the voice. If it loses fullness while the hum barely changes, disable the filter.
5. Compare Original and Processed. If hiss remains, add gentle noise reduction and check again.

Why a buzz may remain

The fundamental may be 60 Hz rather than 50 Hz, or the tone may drift. noise has no separate 60 Hz mode, so the 50 Hz filter should not be treated as a universal solution for electrical noise. A strong buzz may also come with distortion that remains after reducing the tone.

Should you use it for music?

Useful sound can occupy the filtered frequencies too. Compare the tone of music and low voices carefully. Keep the filter enabled only when reducing the hum makes listening easier.

For hiss, start with noise reduction. For several defects together, follow the archive lecture workflow.

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