ACX-Ready Audiobook Audio Polishing

I already have a completed 4-hour audiobook recorded and edited in WAV format.
All I need is for the files to be mastered to ACX / Audible standards — ready for upload.

I don’t need narration, editing, or new recording — just the technical post-production to bring everything into spec and ensure consistent tone and levels across all chapters.

Please only apply if you’ve previously worked on ACX-approved audiobooks or can demonstrate experience meeting ACX’s audio requirements, including:

Peak levels between –3 dB and –3.5 dB

RMS between –23 dB and –18 dB

Noise floor below –60 dB

Output in 192 kbps CBR MP3 (44.1 kHz)

Deliverables:

Each chapter mastered and exported as individual MP3s (ACX-ready)

Consistent tone and loudness across the full 4 hours

One round of minor revisions included (if ACX requests tweaks)

What I’ll provide:

4 hours of WAV files

One “accepted” sample chapter (already passed ACX) as reference tone

What you’ll deliver:

All 4 hours ACX-compliant

Clean, natural sound (no distortion or over-processing)

Turnaround ideally within 1-3 days

Budget:

Open to offers — typically expecting £50–£200 total for mastering (not editing).

Ideal freelancer:

Based in the UK (preferred) or familiar with ACX submission

Has mastered previous audiobooks for Audible

Communicates clearly and works transparently