Increase RMS/Volume without undoing previous Amplify

Hello all!

My client recently requested that I raise the RMS/Volume a smidge in my latest audiobook production. I’ve read that the best way to do this is to simply use the default Amplify as that will raise the volume to just below clipping. Throughout the production there are certain pieces that I have used amplify to diminish but not remove the sound (such as breaths between words or areas where a syllable was a tad loud) to maintain a quality flow.

How can I raise the volume of the entire piece without jeopardizing the amplifies I have already done? Is there a way to increase volume of all audio that has not already been amplified in some way? Or perhaps to raise everything by a percentage rather than a flat amount. If there is a better tool to use than amplify in this case I would love to learn more about it.

Thanks so much for your time and consideration!

Assuming you’re using Audacity 2.1.3 or higher.

We have a (new) pre-baked tool called RMS Normalize that can directly set RMS. Between that and Soft Limiter, you can put your presentation pretty much wherever you wish.

Are you shooting for ACX AudioBook conformance?

That tool will “force” your clip or chapter to a set value. -20dB will put you in the middle of the ACX range of -18 to -23.

Follow that up with built-in Effect > Limiter.

– Effect > Limiter: Soft Limit, 0.00, 0.00, -3.50, 10.00, No > OK.

-3.5dB was chosen instead of -3dB (the official limit) in order to avoid missing conformance in the MP3 conversion step which can mess up volume levels.

I expect those two to push your performance into compliance without being able to hear any change save possibly a volume shift.

Feel free to change the settings around if you’re using a publishing service with differing conformance standards. Post back if you have troubles.


I think I would do this correction chapter by chapter rather than the whole performance at once, but it’s up to you. If you’ve already leveled and processed your work, it may be OK once over the whole show.

Save all original works as WAV protection copies (being obsessive I do it on a thumb drive) in case Audacity or the computer does something messy during production.


Awesome, thanks for the advice!

I guess technically, I didn’t answer the question.

Analyze > Contrast > Measure Selection

…will tell you what the RMS level is now. That will give you a good idea where to set RMS Normalize to get the difference value if that’s your goal.

And yes, certainly, if your blue wave peaks wander too high when you do that, use the Limiter tool to press them back down. Soft Limiter is good. The harder the tool, the more likely it is to be heard.

There is a much older tool called “Leveler” which was so bad at leveling, it was retired from normal effects service and put in distortion effects. We didn’t want to see it go because it was without doubt the best way to get “airplane pilot voice.”