Again you’ve notched the entire audio spectrum, 300+ notches, (rather than 5).
as a result the sound has a strong unintentional reverb(eration) effect.
If you must notch-out all the harmonics so be it,
but I would not do that, as the consequent reverb makes speech more difficult to understand.
I did it with the exact same settings as per your post. Confused.
Could “untouched” have had de-hum applied which has included all the spectrum ?.
If you increase the “window size” to 65536 you’ll see all the notches …
There’s more than 5.
Sample file, direct from PAL Betamax tape capture.
Hum remover applied - new sample clip
“Betamax-sample-NEW-WAV.wav” has not been notched,
The hum remover has to be set 100%, 50Hz, 2 odd, 3 even …
Again un-notched: the constant horizontal lines are the hum …
BTW with the benefit of hindsight 3 odd and 3 even is better (there are 6 strong lines)
I’ve no idea what is going wrong. I select the entire file and apply the filter. Then it takes some time to apply, then I select a small piece and export it to this foum.
I just tried again and it doesn’t seem that the filter (De-hum.ny) is working. I’ve done some googling and I can’t find a way to enable this filter (it’s Nyquist). I will have a try on a PC - I’m doing this on a Mac.
New sample - managed to get the pluging working on an old PC.
ps - thanks for your patience on this 
Nyquist plugins work in Audacity on all platforms: Mac/PC/Linux.
Mains hum still there: the constant horizontal lines at 50,100,150,200 & 250Hz
You can check the spectrogram for yourself to see if the hum is gone.
What am I doing wrong? The filter was applied, it said done when I applied it.
In the sample above, hum threshold is set to 100% - is that correct?
There must be something wrong with the filter I downloaded - it doesn’t seem to work on my Macs or the PC when enabled. Is there an alternative filter?
Yes, 100% …
Could notch out the hum lines with Audcaity’s built in spectral multi tool …
https://manual.audacityteam.org/man/spectral_selection.html#example
but have to do it 6 times.
Just ran a debug on the De-Hum filter - any idea what this means?
The maximum number of sample blocks has been
reached, so audio computation must be terminated.
Probably, your program should not be retaining
so many samples in memory. You can get and set
the maximum using SND-SET-MAX-AUDIO-MEM.
error: audio memory exhausted
1>
At this point, I feel I must give up or I’ll go crazy. I’ll try the effects in Final Cut and DaVinci.
It means the audio you selected is too long for a Nyquist plugin.
A workaround is to divide the audio up into smaller sections and apply the plugin to each section individually.
1 Like
Finally - I’m sure it is now working, I had to split the moive into three parts.
