Hi, Eero,
What medium did you receive this recording on? You said a digitized
copy, how was it digitized? Directly from the video tape or via a
cassette copy of the videotape.
I have heard this type of magnetic record damage in analog audio
cassettes where they were stored out of their jewel boxes in a drawer
that contained magnets.
It is possible that this type of erasure could have occurred directly on
the video tape.
Another thought, it could be poor-tape-to-head contact and you're
hearing spacing loss. I doubt it's azimuth wander, but if the tape was
physically stretched it might be (slim chance).
I think I'd attack this with the dynamic equalizer in Ozone--but no
matter what you do it won't be high fidelity.
I did do one very messy thing where I made several copies and then let
iZotope Neutron mix them, I think it did a passable job, but again, you
can't put back what's there, just improve intelligibility. If this is
music, well, that's too bad. It can sound a bit better. You might also
try a bit of fix on the good stuff too for the access copy: reduce the
highs a bit so the contrast isn't so bad. It might just be more listenable.
Good luck!
Cheers,
Richard
On 2019-04-25 12:14 p.m., Eero Aro wrote:
> Hi All
>
> 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
> to it.
>
> 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
> recording.
>
> 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
> the shortwave
> when I was listening to SW bands as a radio amateur. Similar fading
> occurs on
> medium and long waves as well. But this recording was not recorded from
> a radio,
> 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
> amplifier
> 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
> frequencies
> 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
> area.
> 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
> dropbox.
> https://www.dropbox.com/s/c0n4aojd2w3ou5w/Fading%20screenshot.jpg?dl=0
>
> If anyone is interested to hear a sample of the recording, please email
> me off-list.
>
> Eero
> ----------------------------
> http://www.tonfiks.fi
>
--
Richard L. Hess email: [log in to unmask]
Aurora, Ontario, Canada 647 479 2800
http://www.richardhess.com/tape/contact.htm
Quality tape transfers -- even from hard-to-play tapes.
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