Audio hum filter
Reduce 50 or 60 Hz mains hum and its harmonics with narrow filters, and compare the spectrum before and after.
Accepted files: .wav,.mp3,.m4a,.aac,.flac,.ogg,.oga,.opus,.webm,audio/*. Choose one file. Up to 256 MiB in total.
One recording up to 256 MiB and 10 minutes; 1 to 10 harmonics, depth 3 to 60 dB, Q 5 to 100. WAV is read with every sample intact; other formats are decoded by your browser at 48 kHz. Everything is processed on your device and nothing is uploaded. Download: WAV in the source format or the format you choose, a JSON report and a CSV spectrum up to 1,000 Hz before and after. Notches are placed on the mains frequency and its harmonics. Up to 1,000,000 characters. Review the settings before running.
Your result
How to use Audio hum filter
- Choose the recording with hum.
- Pick automatic detection near 50 or 60 Hz, or a fixed frequency.
- Set how many harmonics to remove and how deep the notches are.
- Filter, compare the spectrum and listen to the result, then download the WAV.
Useful next steps
One recording up to 256 MiB and 10 minutes; 1 to 10 harmonics, depth 3 to 60 dB, Q 5 to 100. WAV is read with every sample intact; other formats are decoded by your browser at 48 kHz. Everything is processed on your device and nothing is uploaded. Download: WAV in the source format or the format you choose, a JSON report and a CSV spectrum up to 1,000 Hz before and after.
Finding the hum
In automatic mode the strongest peak within 3 Hz of 50 or 60 Hz is measured from an averaged spectrum, so a slightly fast or slow mains frequency is followed. With a fixed setting exactly 50 or 60 Hz is used. Europe and most of Asia and Africa use 50 Hz; North America uses 60 Hz.
Notches
A narrow cut is placed on the fundamental and each harmonic up to the number you choose, skipping any above 95 percent of half the sample rate. Higher harmonics get notches that are slightly wider in hertz. A higher Q makes each notch narrower, which keeps more of the voice or music.
Limits
The filter removes steady tonal hum. It does not remove broadband buzz, clicks or noise; for those use a noise reduction tool.