My customer has a digitized audio copy from an old video tape.
I haven't faced this kind of a problem before and cannot find a solution
There is a fading in the high frequencies at a rate of about 1,5 to 2 Hz,
the rate is not steady, it varies and it appears only in parts of the
The high frequencies have been repeatedly attenuated and attenuation
affects down to 6 kHz at places. There is high frequency content in the
recording up to about 15 kHz.
This sounds very similar to a fading interference that I heard a lot on
when I was listening to SW bands as a radio amateur. Similar fading
medium and long waves as well. But this recording was not recorded from
it has been copied from a video tape. I don't know if the audio tracks
have been linear
analog tracks on the tape.
Another way I can try to describe the fading is that you would turn your
gain knob up and down, but the damping would only affect high frequencies.
It is a bit like a longish "dropout" or a fade-out, but the shape of the
in the fade is different to a fade-out in a quarter inch tape.
Does anyone know a way to fix this? I have tried using the Spectral Repair
tool in RX with no success. It is difficult to define such an area, around
which the tool could interpolate stuff into the variably shifting damped
Also, doing it in smaller pieces doesn't work too well.
There is a screenshot of a four second sample of the spectrogram in my
If anyone is interested to hear a sample of the recording, please email