Digital format
Audiobook (MP3 masters)
Retail audiobook masters are usually delivered as one MP3 file per chapter. ACX, for example, requires 192 kbps or higher constant bit rate MP3 at 44.1 kHz, RMS between −23 and −18 dB, peaks no higher than −3 dB and a noise floor below −60 dB.
Tips
- Keep each file under 120 minutes.
- Include opening and closing credits and a 1–5 minute retail sample.