Audio Delivery Spec References
The technical requirements of the major delivery platforms, verified against the official sources and kept current. Every page carries a last-verified date and a link to the original document.
Each reference puts the full spec in one table: loudness target and gating mode, true peak ceiling, noise floor where the platform checks one, and the format requirements. The measurement notes explain how each value is actually computed, because most rejected deliveries fail on the measurement method, not the number. These are the same specs the DubCheck engine tests against, so every value on these pages is one a working audit can verify on your files.
ACX Audio Submission Requirements
RMS level, peak, noise floor, MP3 format, room tone and per-file consistency for audiobook delivery.
EBU R128 Loudness Requirements
-23 LUFS in EBU Mode, -1 dBTP true peak, LRA descriptor and the shortform variant for European broadcast.
Netflix Audio Delivery Requirements
Dialogue-gated -27 LKFS, the 15% low-dialogue fallback, -2 dBTP true peak and format requirements for near-field mixes.
Spotify Audiobooks Requirements
RMS -24 to -14 dB, noise floor under -60 dB, MP3 preferred, mono or stereo, plus credits and retail sample rules from the SFA guide.
Storytel Audiobook Requirements
ACX-compatible levels delivered lossless: RMS -23 to -18 dBFS, -3 dBTP peak, -60 dBFS noise floor, WAV or FLAC, mono preferred.
Prime Video Audio Delivery Requirements
Program loudness -24 LKFS ±2 LU without dialogue gating, -2 dBTP true peak and 48 kHz PCM in WAV or MOV.
ATSC A/85 Loudness Requirements
The CALM Act standard for US broadcast: -24 LKFS ±2 LU program loudness, -2 dBTP true peak and dialnorm metadata.
Spotify Loudness Normalization
The -14 LUFS playback reference, the -1 dBTP ceiling for lossy encoding and the Loud/Normal/Quiet playback modes.
Apple Digital Masters Requirements
-16 LUFS Sound Check reference, -1 dBTP true peak, clipping as a hard fail and AAC 256 kbps conversion headroom.