If you want to learn how to narrate audiobooks on ACX, the process breaks into three parts: get accepted and audition, record to ACX’s technical standards, and deliver finished, mastered chapters. ACX (Audiobook Creation Exchange) is the marketplace that connects narrators with authors and publishers, and it has strict audio requirements you must meet for files to pass review.
Here’s the practical workflow from profile to finished book.
Set up your profile and audition
Create a narrator profile and upload samples that show your narration range — clean, warm, well-paced reads. Authors browse profiles and post titles with audition scripts; you record the audition passage and submit it. Deals are typically structured as either a flat per-finished-hour arrangement or a royalty-share split. Audition consistently and tailor your sample to the book’s tone (a thriller and a cosy memoir need different energy).
Know the ACX audio requirements
ACX rejects files that don’t meet its technical spec, so build your chain around it from the start. The core requirements include:
- Consistent loudness within a defined range, measured in RMS, plus a peak ceiling and a noise-floor maximum.
- Room tone at the head and tail of each file.
- Each chapter as its own file, opening with title/chapter announcements as specified.
- Mono or stereo MP3 files at the required bitrate and sample rate.
Because the exact figures can change, always check ACX’s current submission requirements rather than relying on memory. Understanding loudness helps — see our explainers on LUFS and loudness and sample rate and bit depth.
Build a quiet, dry recording space
The biggest reason files fail is noise and echo. ACX wants a low noise floor and a dry, consistent sound across hours of audio. A treated space is essential — follow our guide on how to build a home voiceover booth. Choose a mic that suits your voice and room; our breakdown of condenser vs dynamic microphones helps you decide.
Record and perform for the long haul
Audiobooks are marathons — many hours of consistent reading. Keep your distance, energy and tone steady across sessions, and re-check your setup if you record over several days. Warm up first using our vocal warm-up routine, hydrate, and punch in to fix mistakes as you go rather than re-recording whole chapters.
Set up your recording chain for spoken word
Once your space is treated, the signal chain itself wants to be simple and clean. Record at the sample rate and bit depth you plan to work in (a higher bit depth gives you headroom while editing, even though the final ACX file is an MP3). Set your gain so that peaks land comfortably below clipping with plenty of room to spare — chasing a hot level at the input only invites distortion and makes consistency harder over a long book. A pop filter is non-negotiable for plosives, and a consistent mouth-to-mic distance matters far more than any expensive piece of gear.
Get into a routine that protects consistency: same mic position, same chair, same time of day if you can manage it. Mark your floor position so you return to the exact spot after a break. Small changes in distance or angle between sessions are audible to listeners and to ACX’s QA team, and they are tedious to fix in the edit. If you record across several days, listen back to the end of yesterday’s session before you start to match your energy and pace.
Edit, master and deliver
After recording, edit out mistakes, mouth noise and long pauses, then process the audio to hit ACX’s loudness and peak targets while keeping the noise floor low. Add room tone, top and tail each chapter correctly, and export to the required format. Mastering for spoken word follows the same logic as our guide to mastering a podcast. Submit, respond to any QA feedback, and you’re done.
How to choose your gear and approach
You do not need a large or expensive setup to pass ACX. Prioritise in this order: a quiet, dry room first, then a microphone that flatters your voice, then editing skill, and only then nicer hardware. A modest mic in a well-treated space beats a premium mic in a reflective, noisy room every time. Most narrators succeed with a single mic, a basic interface, an audio editor they know well, and a pair of closed-back headphones for spotting noise.
When choosing how to work, decide early whether you will record and edit in one pass or batch your recording and edit later. Recording whole chapters and editing afterwards keeps your performance fluid; punching in as you go saves edit time but breaks the read. Pick the method that keeps your tone consistent, because consistency is what ACX’s spec and your listeners reward.
Common mistakes to avoid
- Ignoring the noise floor until the end. If your room is too noisy, no amount of mastering will rescue it cleanly. Fix the space before you record a full book.
- Over-processing. Heavy noise reduction, aggressive EQ or hard limiting to force loudness leaves spoken word sounding thin or pumping. Aim for clean capture so processing can stay light.
- Inconsistent levels between chapters. Master every file to the same loudness target so the book plays back evenly from start to finish.
- Forgetting room tone. Each file needs a short stretch of the room’s natural silence at the head and tail; missing it is a common, avoidable rejection.
- Mismatched takes. Re-recording a single line days later with a different mic distance or tone stands out badly. Match your setup before patching.
Frequently asked questions
Do I need experience to narrate audiobooks on ACX?
No prior credits are required to audition, but you do need clean audio that meets ACX’s specs and a steady, listenable read. Many narrators use audiobooks to build their first credits while developing their craft.
Why do ACX audiobook files get rejected?
Most rejections come from technical issues: loudness outside the allowed range, a noise floor that’s too high, peaks that are too hot, or missing room tone. Building your recording and mastering chain around ACX’s requirements from the start prevents most failures.
Can I narrate ACX audiobooks from a home studio?
Yes — most narrators do. You need a quiet, acoustically dry space, a suitable microphone, and the ability to master files to ACX’s loudness and noise-floor standards. A converted closet or DIY booth is often enough.
How long does it take to narrate a book?
A useful rule of thumb is that each finished hour of audio takes several hours of total work once you include recording, editing and mastering. Budget for that ratio so you can quote royalty-share or per-finished-hour deals realistically and avoid burning out mid-project.
