An ACX-style readiness check
Master your audiobook to the ACX technical submission spec in one click, then read a pass/fail report on every metric a reviewer measures — loudness, peak, noise floor, room tone, and format.
Audiobook stores reject files on technical grounds before a human ever listens: loudness out of range, peaks too hot, a noisy floor, room tone too long. Book Director Studio masters to those numbers for you. The ACX-style preset normalizes loudness, trims the silence AI voices add, and pads room tone to spec, then a readiness report checks the result against the ACX technical requirements and marks each metric pass or fail.
One honest note up front: this measures the technical spec. ACX (Audible’s platform) currently requires human narration and prohibits unauthorized text-to-speech or AI recordings, though Audible has said it is working toward accepting third-party TTS. Meeting the ACX technical bar means your file is clean, consistent, and loudness-correct for submission wherever AI narration is accepted — and it is the same bar reviewers across the industry expect.
One-click mastering
The ACX-style preset normalizes loudness, trims dead air at the edges, and pads room tone — no external editor or audio engineering required.
A pass/fail report
After export, the readiness report measures your file against the ACX spec and marks each metric, so you know it is clean before you submit.
Every key metric
Peak level, RMS loudness, head and tail room tone, and file format are all checked against the published ACX ranges.
Retail sample included
Generate the short retail sample stores request alongside the full book, mastered to the same spec.
Re-check any export
Open the readiness check on any item in your export history to re-measure it at any time.
Honest by design
The report mirrors the ACX checks so you can submit with confidence, but it is informational — the retailer always makes the final call.
- Peak level
- At or below −3 dB
- RMS / loudness
- −23 to −18 dB
- Noise floor
- At or below −60 dB RMS
- Head room tone
- 0.5 to 1 second
- Tail room tone
- 1 to 5 seconds
- Format
- 192 kbps or higher CBR MP3, 44.1 kHz
Ranges reflect ACX’s published audio submission requirements (Audible, updated April 2026). A clean render with the ACX-style preset passes every check.
- Does passing the readiness check guarantee ACX will accept my book?
- No. The check confirms your file meets ACX’s technical specifications. ACX currently requires human narration and prohibits unauthorized text-to-speech or AI recordings, so an AI-narrated file is not eligible there today regardless of its technical quality. The readiness check is most useful for submitting to platforms that accept AI narration, where the same loudness and format standards apply.
- Which numbers does the report measure?
- Peak level (at or below −3 dB), RMS loudness (−23 to −18 dB), noise floor (at or below −60 dB RMS), head room tone (0.5–1 s), tail room tone (1–5 s), and format (192 kbps or higher CBR MP3 at 44.1 kHz).
- Do I need audio software to hit these levels?
- No. The ACX-style export preset masters to these targets automatically. There is no separate editor, plugin, or mastering chain to set up.
- Where can I publish an AI-narrated audiobook?
- Acceptance varies by platform and changes over time, so check each retailer’s current policy before submitting. The readiness check helps ensure your file is technically clean for any platform that accepts AI narration.
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