ACX new????? requirements

Until recently updating my Surface Pro Windows 10 from Audacity 2.2.2 to Audacity 2.3.0, I happily and successfully submitted audiobook MP3 files to

NOW 3 months later will not accept what I have done previously. Their requirements now are for 192kbps MP3 files. They have produced a tutorial advising how this should be done. They suggest exporting files in WAV format and converting them using free download fre:ac software into MP3 files using a LAME MP3 Encoder setting a bitrate of 192 kbps. All of which I find baffling!

IT IS TEDIOUS AND I DON’T WANT TO DO IT as I am quite happy with Audacity. I am NOT A TECHIE and I find it distressing.

I find it difficult to believe that Audacity in updating their software would not be aware of this change as I suspect that many narrators such as myself use Audacity.

My question is :- “How can I use or reconfigure Audacity 2.3.0 to achieve what ACX require?”

Answers in laymans language will be much appreciated.



The MP3 encoding options are set in the MP3 export dialog screen.

At the bottom of the export MP3 settings, you need to select:
Bit Rate mode: => “Constant”
Quality: => “192 kbps”
Channel mode: => “Force export to mono”

(Also, the “Project Rate”, in the lower left corner of the main Audacity window should be set to “44100”)

It is necessary to install the LAME thing into Audacity to make MP3 files,
instructions on how to do that are here …
https: //

If you only are submitting a mono track, is this step necessary?

If your project is mono, then this setting has no effect.
If your project is stereo, then this setting ensures that the MP3 file will be mono.

ACX strongly recommend that submitted files are mono, so enabling this option ensures that your files meet this recommendation. (

Their requirements now are for 192kbps MP3 files.

As far as I know, they have been for quite a while. The bare minimum for any mono presentation is around 32 quality-fixed bitrate. That’s when many people start to hear something wrong with the sound. ACX chooses 192 quality—which seems like overkill—because they are going to recode your work into different products and services and want the quality to hold up.

Also note they don’t say 192. They say 192 or higher. 192 is a minimum.

encoding files to 192kbps or higher MP3, Constant Bit Rate (CBR)

That’s from their web page.

They suggest exporting files in WAV format and converting them

We have another possibility. Export your work (chapter) as WAV (Microsoft) 16-bit and then Export it again at 192 quality MP3. You don’t need to involve a separate software product or step. The WAV is your Archive Master. You can throw the MP3 away after you submit. You can’t edit or process an MP3 without loss of quality. You can convert a WAV into anything.

In addition, it’s strongly recommended that you Export raw readings as WAV before you process or master them. This is against the time that Audacity or your computer fails during Corrections or Mastering. If it fails just right without that WAV file, it could destroy the work and you could be stuck reading it again.

ACX recommends submitting everything the same, either stereo or mono, but they have a preference for Mono—one blue wave. So do we. Processing is faster, storage is more efficient, the ACX-Check panel is much simpler and you don’t need the Force Convert to Mono step at the MP3 export.


I don’t think you ever said you were using ACX Check for your work. Are you?


Steve and others

Thank you very much for your help. Yes I do use ACX Check extensively. Narrating audiobooks with many voices would be impossible without doing so.

Best wishes for Christmas and New Year from across the Pond