When to export WAV vs. MP3?

When to export WAV vs. MP3?

This is a question I get frequently from my students. And it's a reasonable one. I have a simple rule of thumb when it comes to determining which is appropriate:
Will the recipient of the audio need to make changes to the audio?
If the answer is "yes", then – in general – you should provide them with the WAV file. Of course, there will always be exceptions, but this is a great starting point. 

It's good to understand the general difference between the two formats. A simple Google search will provide more detailed information, but for the sake of simplicity, here is an overview. WAV format is what is referred to as "lossless". This means that rendering the audio in this format will result in no loss of data and, therefore, a larger file of higher quality. MP3 format is "lossy", meaning that rendering to MP3 will "throw away" some data in determines isn't necessary for the sake of creating a smaller file. The process will result in some loss of quality. The logic behind our rule above is that we want to maintain the highest degree of quality throughout the production process, saving rendering to MP3 as the final step before submitting it.

Here are some common audiobook production scenarios and the format to which the audio should be rendered:
  • Deliver audio to Proofer:  Using the rule of thumb we described in the previous paragraph, we ask ourselves if the proofer needs to make changes to the audio. The answer is "no". The proofer will listen to the audio and review the manuscript, noting any issues that are encountered; therefore, we can provide MP3s.
  • First 15: The rights holder will listen to the audio but is not making any changes to it. For that reason, we would provide the Rights Holder with the audio in MP3 format.
  • Deliver Audio to Editor: the editor will make significant changes to the audio including removal of noise and trimming audio for the sake of narrative flow. The editor should receive WAV files.
  • Export before RX batch: if you are mixing down your audio as he stepped prior to running it through a batch in RX, the audio should be in WAV format since we are changing the audio. We expect the batching process to clean up many of the issues in the audio for us.
  • Upload final files to ACX: This is the exception to the rule. ACX requires that the final version of the audio be delivered as MP3 despite the fact that they will perform some degree of processing on the audio to prepare it for retail.