Workaround for inability to export projects?

I love Audacity and don’t know what I’d do without it, but am now having a tiff with it. I have recently downloaded some mp3 audio lectures that I attempted to listen to while commuting in the car. Unfortunately they’re too quiet and can’t quite be heard above the ambient noise of an auto on the freeway. I wanted to use Audacity to chain an amplitude increase (my multimedia workstation is getting a bit old so yes, on this version of Audacity it’s a “chain” rather than a macro–but I like the old version better anyway).

The problem is that peaks are different in each file. In some files the maximum amplification before clipping goes up to 1.5; in others it dips down to about .8 and therefore each file needs to be amplified separately on a case-by-case basis, so a chain won’t work to do this. But I was hoping that at least I could avoid the tedium of sitting through 30 seconds to a minute of Export. These are long, ca. 40-minute files, and they take a long time to export. I wanted to make the amplitude changes in a bunch of Audacity project files and then use a chain just to apply Export on those projects, assuming that it would export the amplitude changes too. Then I could just walk away from the machine for a good 15 minutes while it took care of all that exporting.

Never having had occasion to batch Audacity projects before, I didn’t know you couldn’t–and, unhappily, now I do. This really sucks. Is there a way to do what I want, or am I stuck going through each d—d lecture and having to sit through the exports?

Add RMS normalize plugin in your chain, followed by a limiter, (without make-up gain) .

[The latest Audacity has native LUFS Loudness normalization, which more consistent than RMS]

Thanks Trebor. Argh, maybe I’ll try LUFS on a different machine. If I do that, do I still need to use a limiter or is the normalization sufficiently consistent that a limiter isn’t necessary?

RMS normalization can result in some peaks going over 0dB, i.e. clipping
If RMS normalization is followed by a (soft) limiter, at say -1dB, without make-up gain,
then any clipping is avoided.

NB: RMS normalization and normalize are different things, not equivalent.

RMS normalization demo …
rms demo

Programs like Mp3Gain can raise the volume of your MP3 files without re-encoding.

Thanks for the additional details about limiting RMS normalization. I’m a big proponent of knowing the ins and outs of a process, so that’s not just polite handwaving. However, it doesn’t answer the question I actually asked, which was about your second alternative. If Iuse the LUFS loudness normalization on a new Audacity on a different machine, can I assume that it’s self-limiting so the additional limiter isn’t required?

Hey Wrecks, thx for the additional possibility. The more options, the better.

Audcaity’s native* LUFS effect does not have a limiter built-in.
[ * (t’s not a plugin that can be used in old Audacity like the RMS normalize ] .