Mixdown Question

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@twilightsong

@Split

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Heres a good PDF explaining the more technical aspect of Dithering in Audio, also contains an explanation of the UV22 dither and how it got it’s name
http://www.users.qwest.net/~volt42/cadenzarecording/DitherExplained.pdf

That article is from way back in 2002 which means, in the words of a famous physicist, “it’s not even wrong!”

Nothings changed since 2002 as far a dithering digital signals and the reasons it’s required.

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@braunie

And if you are mixing otb every output channel should have it as well during mixdown.braunie

If you’re going to dither more than once then “coloured” (UV22 or any other shaped dither) should not be used, acording to that article. Coloured dither should only ever be applied once and that would be the very last process done.

[Scab_Pickens]

@Chris Beuermann

Hello Scap you are right

It’s all good

[mroekalea]

So basically if I were to ever mixdown to 44.1/16 for burning to CD I should be using it but “don’t bother otherwise”…?

When the sources are already in 44.1khz then I wouldn’t use dithering, only when I have a diffrent samplerate and bitdepth I use UV22HR as last insert on the masterbus when exporting the mix.

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@mroekalea

So basically if I were to ever mixdown to 44.1/16 for burning to CD I should be using it but “don’t bother otherwise”…?

When the sources are already in 44.1khz then I wouldn’t use dithering, only when I have a diffrent samplerate and bitdepth I use UV22HR as last insert on the masterbus when exporting the mix.

Sorry, this is wrong.

The output from the masterbuss will always be 32bit float regardless of the source bit depth.

The only exception would be if there is absolutely no processing from source to masterbuss including no gain changes.

[foolomon]

@foolomon

@twilightsong

@braunie

And if you are mixing otb every output channel should have it as well during mixdown. The question whether it is needed for mp3’s is a good one thou’

braunie

Okay, but what if your D/A is running at 24-bits? I wouldn’t think you need it in such a case

My default project as the UV22 installed on the last slot of the master, and muted… until time to export to 16-bit. I believe it should be used when going from 24-bit to mp3 since you’re reducing bit-depth

You’re correct about the reduction in bit depth giving you reason to consider it, but if you read the article you’ll realize that the dithering is done to reduce the noise floor due to round off error during the bit reduction. MP3 already introduces changes to the signal due to its own reduction algorithm so I’m not sure dithering is going to buy you anything. It may even degrade the sound because of some adverse interaction between the codec and the dithering…who knows?

I should test this out since I have the frequency analyzer VST.

Does the test tone plug-in generate a sine wave? If so, I’ll use it to generate an MP3 and do a frequency analysis on the result to see whether we get the same high noise floor as was illustrated in the article (and, hence, would require the use of dithering).