Garageband setting for RMS (dB) for ACX audiobook specs

Question

Garageband setting for RMS (dB) for ACX audiobook specs

I am preparing an audiobook for ACX-Audible. I have created very clean audio files, and solved nearly everything...

But the site is not accepting some of the files.

I have been searching the threads here, and cannot find a solution. Some issues are for older versions of Garageband, and I can't solve the issue.

Below is a screengrab.

The column with the specs in PINK doesn't meet the requirements. I am not sure what RMS (db) means, or how to solve this.

Can anyone help? Thanks in advance!

(I'm using Garageband version 10.4.6)

of the notice for ACX-Audible

Posted on Mar 20, 2022 12:08 PM

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Answer 1

Top-ranking reply

Mike Clelland Author

Level 1

19 points

Mar 20, 2022 4:09 PM in response to Keith Barkley

I solved it. I re-uploded the files after clicking one box in the garageband preferences. I clicked "export project at full volume" and it worked! ACX accepted the files after this one change.

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Answer 2

Mar 21, 2022 2:33 PM in response to BDAqua

This issue has been an ongoing quandary from the users here. I think this is a very simple solution.

The simplest option seems to be to "export project at full volume" for each audio track.

I hope this thread helps other users!

Best,

Mike

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Answer 3

Mar 20, 2022 1:34 PM in response to Mike Clelland

Assuming that is RMS over the whole chapter, there is no way to do that in GarageBand without a plug-in.

I suggest you ask ACX if they know of a tool that will let you calculate this.

Otherwise it appears that they want above -23 dB, or it is too quiet. So, what you need to do is take, for example, chapter 3, and boost the level by about 1.5 dB which should take the -24.1and make it -22.6 or so.

It appears Audacity will do it:

https://manual.audacityteam.org/man/measure_rms.html

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Answer 4

BDAqua

Level 10

245,507 points

Mar 20, 2022 1:01 PM in response to Mike Clelland

Perhaps help here in understanding?

RMS = root-mean-square

PEAK level does not take TIME into account. PEAK level only looks at one "moment" in time.

RMS Level "averages" PEAK readings over time and thus gives you an idea of average level. RMS level is a also a much better (although far from ideal) indication of perceived volume than peak level.

Below -8 dB average RMS but looks like -12 dB RMS on the wave form.

By eg manipulating a lot of bass into a mix it is possible to get ridiculous RMS values.

I was informed that the Peak rating is what the equipment could, in a research laboratory under test conditions, be capable of given a particular signal level absolutely optimised for input.

The RMS power rating is a measure of continuous power and means the device is either able to provide or accept the specified power over a significant length of time without failure.

And more..

https://gearspace.com/board/mastering-forum/352357-when-someone-says-12db-rms.html

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