Multi level Equalisation settings for Dolby B replay

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Multi level Equalisation settings for Dolby B replay

Permanent link to this post Posted by simonron » Sun Sep 17, 2017 12:39 am

Hi

I have a mass of Reel to reel music tapes recorded in Dolby B using a now dead hardware box. Is there a pre built set of EQ curves for Audacity that I could run my tapes through? Many have Zero DB lineup tone which should help.

If not, can someone tell me how to make multiple filters? So far I can only make one per file. Can I create lots and run the together ?
Thanks
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Re: Multi level Equalisation settings for Dolby B replay

Permanent link to this post Posted by kozikowski » Sun Sep 17, 2017 12:52 am

Many have Zero DB lineup tone which should help.

It helps line up the Dolby Decoder. It doesn't do you any good at all.

Dolby is a dynamic processor. It treats low volume sounds different from higher volume ones by a secret recipe. It was the first commercial sound compression and noise reduction system you couldn't hear working. It made tape multi-tracking possible.

https://sourceforge.net/projects/dolbybcsoftwaredecode/

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Re: Multi level Equalisation settings for Dolby B replay

Permanent link to this post Posted by cyrano » Sun Sep 17, 2017 8:58 am

There are a lot of plugins that could do Dolby-B or even C. Only, because of licensing issues with the name, they don't call it "Dolby". To use the name, they'd have to pass tests and pay for licensing. Very expensive and impossible to digest by a small market share.

Stereo tool, U-HE Satin en Overloud Dopamine can do Dolby-B decoding. Even the pluigns that are included with REAPER or Cubase are capable of doing that, but it requires some setup. Example for Cubase:

https://www.soundonsound.com/techniques/bright-idea

Personally, I adjust by ear. Just use an eq from 4 KHz with a -6 dB curve. Adjust to taste. It's not as if most cassettes still are pristine. I've never encountered one that didn't have some hiss added, lower level and loss of high frequencies after 20 years. Some fiddling is always necessary.
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