Master Your Audiobook for Authors Republic Submission

What Are Authors Republic's Audio Requirements?

Authors Republic requires each audiobook chapter file to have an RMS loudness between -23 and -18 dBFS, a true peak below -3 dBFS, and a noise floor below -60 dBFS. Files must be MP3 format at 192 kbps constant bit rate (CBR) or higher, at a 44.1 kHz sample rate. Authors Republic accepts both mono and stereo files, but the channel configuration must be consistent throughout the entire audiobook: all chapters must be either mono or all stereo, not a mix of both. Each file must have 1 to 5 seconds of silence at the beginning and 1 to 5 seconds of silence at the end.[1] Authors Republic also enforces a maximum file size of 170 MB and a maximum duration of 119 minutes per file.[1]

How Does ChapterPass Handle Authors Republic Requirements?

ChapterPass produces ACX-compliant MP3 files that meet all Authors Republic loudness, peak, and noise floor requirements. ChapterPass adjusts RMS loudness to the -23 to -18 dBFS range, limits true peak to below -3 dBFS, manages the noise floor to below -60 dBFS, and outputs mono MP3 at 44.1 kHz with 192 kbps CBR encoding. For head silence, ChapterPass adds 1.0 second, which falls within Authors Republic's 1 to 5 second range and also satisfies ACX's 0.5 to 1 second requirement. For tail silence, ChapterPass adds 1.5 seconds, well within the 1 to 5 second range both platforms accept. Files mastered by ChapterPass for ACX are ready for Authors Republic submission without any additional processing.

What Is Different Between Authors Republic and ACX?

Authors Republic differs from ACX in several specific ways. Authors Republic requires all chapters within a single audiobook to use consistent channel configuration: every chapter must be either mono or stereo, not a mix of both formats. ACX simplifies this by requiring mono only, but Authors Republic gives narrators the option of stereo submission as long as consistency is maintained across the entire title.

Authors Republic enforces a maximum file size of 170 MB and a maximum duration of 119 minutes per chapter file.[1] ACX does not publish specific file size or duration limits. For most standard audiobook chapters, which typically run 20 to 60 minutes, these limits are not a concern. Long-form chapters or compilation files that exceed 119 minutes would need to be split before submitting to Authors Republic.

The head silence requirement is different between the two platforms. ACX requires 0.5 to 1 second of silence at the beginning of each file[2], while Authors Republic requires 1 to 5 seconds.[1] ChapterPass adds 1.0 second of head silence, which satisfies both ranges: it meets ACX's upper limit and Authors Republic's lower limit.

Authors Republic also provides an Audio Track Validation Report that checks submitted files against their requirements before the title goes live. This validation report identifies specific technical issues in individual chapter files, similar to how ChapterPass verifies every output file against all specification checkpoints before allowing download. Narrators distributing through both platforms can also submit the same files to Findaway Voices and Google Play Books, which accept the same or less restrictive audio specifications.

Can You Submit the Same Files to Both ACX and Authors Republic?

Yes. ACX-mastered files meet all Authors Republic audio requirements. ChapterPass adds 1.0 second of head silence, which falls within Authors Republic's 1 to 5 second requirement and also satisfies ACX's 0.5 to 1 second requirement. Both platforms accept MP3 CBR at 192 kbps or higher, at 44.1 kHz sample rate, with the same loudness, peak, and noise floor specifications. The mono output ChapterPass produces is accepted by both ACX and Authors Republic. Narrators who master their audiobook files with ChapterPass can submit the same files to ACX, Authors Republic, and Findaway Voices without reprocessing or re-encoding.

Sources

1. Authors Republic Audio Requirements
2. ACX Audio Submission Requirements