Audio Book Mixing
Post-production of your recorded narration: edited, proofed, pickups reintegrated, and finished to exact Audible/ACX spec, so your files pass review the first time.
Editing, QC against the manuscript, de-breathing and mouth-noise cleanup in iZotope RX, RMS -23 to -18 dB, peaks under -3 dB, noise floor below -60 dB, chapter-split and retail-ready.
Audiobook mastering to Audible/ACX spec
This is post-production for audiobooks, not recording or narration: you bring the recorded voice files, I finish them. Audible rejects audiobooks that miss its technical spec, so I edit the narration, run a proofing and QC pass against the manuscript, reintegrate any pickups, master to ACX targets, and run an anti-rejection check (RMS, peak, noise floor, room tone) before delivering chapter-split files ready for submission.
Good audiobook post-production is invisible to the listener: the performance comes through, the technique does not. Editing stays faithful to the narrator's delivery: de-breathing without making the voice sound airless, removing mouth noise and clicks in iZotope RX while keeping warmth, and spacing sentences and chapters so the rhythm feels natural rather than clipped.
Long-form narration has its own demands. I match levels and tone chapter to chapter so the book never jumps in loudness, hold the voice steady as the narrator's energy shifts across a long session, and reintegrate pickups so re-recorded corrections sit invisibly inside the original take. The result reads as one continuous performance from the first chapter to the last.
What You Get
- Consistent vocal quality throughout
- Professional chapter organization
- Noise reduction and cleanup
- Industry-standard formatting
- Distribution-ready files
- Detailed quality assurance
Audiobook editing and mastering is the post-production stage that finishes already-recorded narration to Audible/ACX standards. It covers editing, a proofing and QC pass against the manuscript, reintegration of pickups (re-recorded corrections), de-breathing and mouth-noise cleanup, consistent levels chapter to chapter, and retail-ready delivery. It does not include recording or narrating the book itself. Work is delivered remotely worldwide and on-site in Paris. To ACX/Audible spec, final files are mono 192 kbps MP3 at 44.1 kHz, RMS between -23 and -18 dB, peaks under -3 dB, noise floor below -60 dB.
At a glance
| Delivery format | Mono 192 kbps MP3 at 44.1 kHz (to ACX/Audible spec); WAV master on request |
| ACX loudness | RMS -23 to -18 dB, peaks max -3 dB, noise floor below -60 dB |
| File structure | One file per chapter or section, each section under 120 minutes, with opening and closing credits (to ACX/Audible spec) |
| Room tone | 0.5 to 1 second at head, 1 to 5 seconds at tail |
| Platforms | Audible (ACX) and other audiobook distributors, Google Play Books, Spotify Audiobooks, self-hosted |
| Tools | Pro Tools and iZotope RX |
| Location | Remote worldwide and on-site in Paris |
ACX delivery specification
| Parameter | Requirement |
|---|---|
| RMS | -23 dB to -18 dB |
| Peak | No higher than -3 dB |
| Noise floor | Below -60 dB |
| Format | Mono 192 kbps MP3 at 44.1 kHz |
| Section length | Under 120 minutes |
| Room tone | 0.5 to 1 s head, 1 to 5 s tail |
hanna-eng.com audiobook mixing FAQ
My Process
From recorded chapters to finished audio book
Content Organization
Importing and structuring all recorded narration files in Pro Tools, one session per chapter or section, so the whole book is organised and ready to edit against the manuscript.
Voice Consistency
Editing the narration: de-breathing, removing mouth noise and clicks in iZotope RX, and tightening sentence and chapter spacing so the pacing reads naturally without sounding clipped.
Chapter Assembly
Proofing and QC pass against the manuscript to catch misreads, doubled words and dropped lines, then reintegrating any pickups (re-recorded corrections) so they match the surrounding take in level and tone.
Quality Control
Mastering to ACX targets with consistent levels chapter to chapter, then an anti-rejection check on RMS, peak, noise floor and room tone so the files meet Audible's review the first time.
Final Production
Delivering chapter-split, retail-ready files in industry-standard formats to ACX/Audible spec, with a WAV master on request.
Audiobook mastering pricing (ACX / Audible)
Three packages built to ACX and Audible requirements, from €75. Editing and chapter splitting included.
Essential
- Program up to 15 min
- Editing and cleanup included
- Chapter splitting
- 1 music track
- Delivered in 2 days
- Meets ACX / Audible standards
Standard
- Program up to 30 min
- Editing and cleanup included
- Chapter splitting
- 2 music tracks
- 1 revision included
- Delivered in 3 days
- Meets ACX / Audible standards
Premium
- Program up to 60 min
- Editing and cleanup included
- Chapter splitting
- 4 music tracks
- 1 revision included
- Delivered in 4 days
- Meets ACX / Audible standards
- Additional revision: +€10
- Payment by bank transfer
- Delivered formats: WAV, MP3
- VAT not applicable (art. 293 B CGI)
Ready to Bring Your Book to Life?
Let's create an audio experience that does justice to your written work.
Frequently Asked Questions
Do you master to ACX / Audible requirements?
Yes, final files meet ACX standards: RMS between -23 dB and -18 dB, peaks no higher than -3 dB, and a noise floor below -60 dB, delivered as mono 192 kbps MP3 at 44.1 kHz with correct head and tail room tone.
Will my files pass Audible's review?
Files are checked against ACX's technical requirements before delivery so they're ready to submit; if anything is flagged, I'll correct it.
How do you keep the voice consistent across a long book?
Chapter-by-chapter levelling and tonal matching in Pro Tools, with iZotope RX for cleanup, managing fatigue-related variation so the whole book sounds even.
What do you deliver?
Chapter-split, retail-ready files (plus an opening / retail sample on request), formatted to your platform's specification.
Do you only work with Audible/ACX?
ACX/Audible is the most common, but the same process suits other audiobook distributors, Google Play Books, Spotify Audiobooks and self-hosted distribution.
What are ACX's file structure rules?
One audio file per chapter or section, each section under 120 minutes, opening and closing credits, and room tone of 0.5 to 1 second at the head and 1 to 5 seconds at the tail. A WAV master can be provided alongside the MP3s on request.
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