Blog
Technical guides for getting your audiobook accepted on the first try.
ACX Human Narration Policy: Can You Use AI Voices for Audible?
ACX prohibits AI-generated and text-to-speech narration. Only human voices are accepted, with one narrow exception: ACX's own narrator voice replica beta.
Audiobook Mastering vs Editing: What's the Difference?
Editing removes mistakes and cleans your audio. Mastering sets the technical levels for platform submission. Here's what each one does, when each happens, and why you need both.
Audiobook Format Requirements: MP3 Settings, Sample Rate, and Platform Specs Explained
The exact file format specs every audiobook platform requires. MP3 192 kbps CBR, 44.1 kHz sample rate, mono vs stereo, bit depth, and cross-platform differences explained.
Audiobook Production Workflow: From Recording to Retail-Ready Files
The end-to-end audiobook production workflow from recording setup through editing, mastering, and platform submission. A hub guide linking to detailed resources for every stage.
How to Self-Publish an Audiobook: The Complete Guide for Indie Authors
Everything indie authors need to know about self-publishing an audiobook. Production options, platform choices, costs, technical preparation, and the submission workflow explained.
How to Fix Every ACX Rejection Issue: The Complete Troubleshooting Guide
A decision-tree troubleshooting guide for any ACX rejection. From the rejection email to the specific fix, step by step. Covers every technical and quality failure.
ACX Rejection for Loudness/RMS: Causes, Measurement, and Step-by-Step Fixes
Your audiobook was rejected for RMS loudness. Here's exactly why it happened, how ACX measures loudness, and the step-by-step process to fix it and pass on resubmission.
ACX Rejection for Noise Floor: Causes, Measurement, and Fixes
Deep dive into noise floor rejections from ACX. Why your noise floor exceeds -60 dBFS, how to measure it accurately, and specific fixes that work without ruining your audio.
Audacity ACX Settings Guide: Effect Chain, Export Settings, and Macros
The exact Audacity settings for ACX compliance. Every effect, every parameter, plus a ready-to-use macro that automates the entire mastering chain.
Audacity Audiobook Mastering Tutorial: Complete Step-by-Step Guide
A complete tutorial for mastering audiobooks in Audacity. Step-by-step instructions with specific settings for every effect, from raw recording to ACX-ready MP3.
Audiobook Chapter Formatting Guide: File Naming, Silence, Sections, and the Retail Sample
How to format audiobook chapters correctly for ACX and other distributors. File naming conventions, silence padding, section breaks, credit files, and the retail sample chapter.
Audiobook Distribution Platform Comparison: ACX, Findaway, Author's Republic, and More
A detailed comparison of audiobook distribution platforms including ACX/Audible, Findaway Voices, Author's Republic, Google Play Books, and Kobo. Requirements, royalties, reach, and strategy.
Audiobook Loudness: The Complete Guide to RMS, LUFS, and dBFS
Everything about audiobook loudness: what RMS means, how it differs from LUFS and peak levels, what ACX requires, and how to measure and adjust your levels correctly.
The Complete Guide to Audiobook Mastering
Everything you need to know about audiobook mastering: the full signal chain, tools, techniques, and how to achieve professional results that pass ACX quality control.
Audiobook Mastering vs Mixing: What's the Difference?
Mixing and mastering are different stages of audio production. Here's what each one does for audiobooks, when you need them, and which one actually matters for ACX.
Audiobook Noise Floor: The Complete Guide to Achieving -60 dBFS
Everything about audiobook noise floor: what it is, why ACX requires -60 dBFS, how to measure it accurately, and how to achieve it in any recording environment.
Audiobook Silence Padding Explained: Head/Tail Requirements, Room Tone, and Crossfades
Everything about silence padding in audiobooks. ACX head and tail silence requirements, why room tone matters, digital silence problems, crossfade techniques, and how to get it right.
Audiobook True Peak Explained: What It Is, Why It Matters, and How to Control It
What true peak is, how it differs from sample peak, why ACX enforces a -3 dBFS true peak ceiling, and how to measure and control true peak in your audiobook files.
Best Audiobook Mastering Tools Compared (2026)
Honest comparison of audiobook mastering tools: DAWs, plugins, and automated services. What each one does well, where it falls short, and which fits your workflow.
Free Audiobook Quality Checker: How to Verify Your Files Before Submission
A complete guide to checking audiobook quality for free. Tools, what to check, manual verification methods, and how ChapterPass automates the entire process.
How to Fix Audiobook Loudness: Too Quiet, Too Loud, and Inconsistent Chapters
Practical guide to fixing every audiobook loudness problem. Step-by-step processes for files that are too quiet, too loud, or inconsistent between chapters.
ACX vs Findaway: Audio Requirements Compared
Side-by-side comparison of audio requirements across major audiobook distribution platforms. ACX, Findaway Voices, Author's Republic, and others.
How to Prepare Your Audiobook for ACX Submission
End-to-end guide from recording to submission. What to do before, during, and after mastering to give your audiobook the best chance of acceptance.
What ACX Actually Checks When You Submit an Audiobook
ACX checks more than loudness and peaks. Here's the full picture: the automated technical checks and the human quality review, so you know exactly what to prepare for.
What ChapterPass Does (and What It Doesn't)
An honest look at what ChapterPass handles and what it can't do. Technical mastering vs recording quality. Know the difference before you upload.
ACX Audio Requirements: The Complete Technical Guide
Every technical spec ACX checks when you submit an audiobook. RMS loudness, true peak, noise floor, sample rate, bit depth, format, and silence requirements explained.