RMS Normalize

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ChasEnglish
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Re: RMS Normalize

Post by ChasEnglish » Tue Nov 26, 2019 2:48 pm

Steve,

Thank you so much. That was an incredibly clear explanation. Took me a bit to reread the math, til it sunk in, but I get it now. All very interesting.

-- Chas

ChasEnglish
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Re: RMS Normalize

Post by ChasEnglish » Thu Dec 12, 2019 1:03 pm

Steve,

If I do an RMS normalization, then do a Peak normalization on the results, the RMS normalization changes to the point where it no longer passes the ACX Check that it passed before Peak was applied.

Is there a mathematical best practices to combine RMS and Peak so both pass ACX Check? Do I first check for peak value, then use that in my RMS calculation in some way?

Chas

steve
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Re: RMS Normalize

Post by steve » Thu Dec 12, 2019 2:11 pm

ChasEnglish wrote:
Thu Dec 12, 2019 1:03 pm
If I do an RMS normalization, then do a Peak normalization on the results, the RMS normalization changes to the point where it no longer passes the ACX Check that it passed before Peak was applied.
That is to be expected. The RMS normalize amplifies the audio to the specified level (based on the RMS level), and then Peak normalizing amplifies it again to a different level (based on peaks), so the RMS normalization has been overridden.

I'm guessing that after RMS normalizing, the peak level is too high. Is that correct?
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kozikowski
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Re: RMS Normalize

Post by kozikowski » Thu Dec 12, 2019 5:16 pm

You're not following Audiobook Mastering.

RMS Normalize sets the overall loudness and then Limiter (not peak normalize) reduces only the peaks so they pass ACX.

https://wiki.audacityteam.org/wiki/Audiobook_Mastering


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Koz

kozikowski
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Re: RMS Normalize

Post by kozikowski » Thu Dec 12, 2019 6:14 pm

If the eventual goal is audiobook processing, there are some real-world problems that should be addressed.

Past the obvious one of setting loudness with RMS-Normalize and then adjust the peaks with Limiter, you also should get rid of rumble and low pitch tones before those tools. That's what Equalize does. It's called Filter Curve in the latest Audacity.

Home Microphones like to create their own rumble and low pitch noise in addition to picking up room noise. Those noises can throw off RMS Normalize and Limiter.

After you finish mastering you may find that the background noise is too loud. Home performers never pass noise. It's hard to get the background noise 1000 times quieter than your voice.

Koz

ChasEnglish
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Re: RMS Normalize

Post by ChasEnglish » Thu Dec 12, 2019 7:48 pm

Steve: I did RMS first, then Peak, so Peak was perfect, but RMS got too low. But...

Koz: Thanks for that link. I'm new to this, had not read the Audiobook Mastering post. I'm trying to follow the math of all this, the page was helpful. Learning about limiters now. Appreciate both yours and Steve's patience as I learn.

-- Chas

steve
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Re: RMS Normalize

Post by steve » Thu Dec 12, 2019 8:15 pm

ChasEnglish wrote:
Thu Dec 12, 2019 7:48 pm
Steve: I did RMS first, then Peak, so Peak was perfect, but RMS got too low.
So applying peak normalization pushed the level down. That means that the peaks were too high, so what you need to do is to reduce the peaks without affecting the RMS (or at least, not affecting the RMS too much. To do that, use the Limiter to reduce the peaks. To minimize audible effects of the Limiter, use the "soft limit" option.

Note that limiting will have a small affect on the RMS level, but unlikely to have a big enough effect to be a problem.
9/10 questions are answered in the FREQUENTLY ASKED QUESTIONS (FAQ)

kozikowski
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Re: RMS Normalize

Post by kozikowski » Thu Dec 12, 2019 8:38 pm

Limiter > Soft Limit is the magic one.

Anybody with a ruler, an adding machine and strong coffee can figure out RMS.

How do you intentionally distort a voice wave so the peaks never exceed a set value but without changing overall loudness (RMS) significantly—and do it so nobody can hear the change or tell what you did?

There was an early peak processor called "Leveller." It was OK, but it used brute force techniques that weren't always satisfactory. It's still available in the tool kit under Effects > Distortion.

Koz

rijkardo
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Re: RMS Normalize

Post by rijkardo » Thu Feb 13, 2020 4:08 pm

Hello everyone,

After about two hours clicking around in circles...here goes with a very low-level question. How do install RMS Normalize?

I have been up and down this link: https://manual.audacityteam.org/man/ins ... st_install

However I cannot for the life of me find where I can actually GET this Nyquist Plug-In Installer that is repeatedly mentioned. Does anybody have a link?

I tried to do it manually per the instructions, but when I go to Library/Application Support I don't see Audacity listed....is there somewhere else it could be hiding? I tried searching and clicking through everything...

I am on latest Mac Catalina 10.15.3 and Audacity 2.3.2.

Many thanks in advance,
Richard

waxcylinder
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Re: RMS Normalize

Post by waxcylinder » Thu Feb 13, 2020 4:43 pm

rijkardo wrote:
Thu Feb 13, 2020 4:08 pm
However I cannot for the life of me find where I can actually GET this Nyquist Plug-In Installer that is repeatedly mentioned. Does anybody have a link?
Since 2.3.1 it's part of Audacity in the Tools menu - go to Tools > Nyquist Plug-In Installer

WC
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