Audio Production Resources

Video Lessons & Resources

ACX requires finished retail-ready audio—rough, unedited narration won't cut it. Whether you’re new to audiobook performance or are a seasoned narrator hoping to become a more proficient producer, study up on our ACX Audio Submission Requirements, and then watch these helpful video tutorials to see exactly how to get that high-quality result. Then, visit the ACX blog for even more video instruction.


Encoding is the last step before you upload your audio files to ACX. In order for your audiobook to be released for sale, it needs to be encoded as, at a minimum, 192kbps CBR MP3s. The entire audiobook must be either mono or stereo, not a combination. We recommend mono, as it reduces the chance of problems like phasing, accidental pans, etc.

There are many DAWs and other tools available to let you encode. Some are easier to use and produce more reliable results than others.

Covered Requirements:

Before You Begin

Before converting to MP3, back up your work! We highly recommend saving a "final" version of your audiobook before beginning the encoding process. It's best to archive your completed audiobook's contents as individual WAV files (broken up by section) with the following properties:

  • Sampling rate: 44.1 kHz
  • Bit depth (or bit rate): 16 bit
  • A length of 120 minutes or less

If a section is over 120 minutes long, find a good break in the narration, and split it into two files. If the section began with a header, such as "Chapter 2", start the second file with "Chapter 2 continued". This will help listeners easily navigate between sections.

Here’s the optimal way to back up your audiobook

  1. Have a master folder that will contain all of your audiobook productions.
  2. Create a folder for your audiobook in the master folder.
  3. Export each section of your audiobook as a WAV, with the specs above, to this folder.
  4. Name each file with its section number first, then the section name.
    1. Ex: 00_Opening Credits.wav, 01_Introduction.wav, 02_Chapter-01.wav, etc.
  5. After naming all the files this way:
    1. Drop the exported WAVs into your DAW.
    2. Look at the entire waveform of each file to make sure there are no accidental gaps or glitches.
    3. Listen to the beginning of each file to ensure it has the correct credits and/or section header.
    4. Listen to each file’s tail to ensure there’s proper spacing and no narration from the next section.
  6. For safety, copy this folder and make a backup on an entirely different hard drive. This reduces the chance of losing your work in case one of the hard drives fails.

Encoding Your Audiobook

  1. In your DAW, open the project with the section you wish to encode.
    1. Most DAWs use the words “Export” and “Bounce” to refer to encoding.
  2. Highlight the track and make sure it has the correct start and end range.
  3. Go to your DAW's encoding menu.
  4. Make sure your encoding is set to export as:
    1. Constant Bit Rate MP3
    2. Bitrate of 192, 256, or 360kbps
    3. Check that all files are either mono or stereo (mono is recommended)
  5. Set your encode/export/bounce directory to the folder you made for this production.
  6. Encode the file.

Congratulations! Your audio files are now ready for submission.