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Message: [QUOTE="Queen, post: 90562, member: 27"] [SIZE=17px][COLOR=rgb(15, 15, 15)]Apple wants a BWF ADM file at 24-bit and 48 kHz, with integrated loudness no higher than -18 LKFS and true peak no higher than -1 dBTP. Miss any of those and the delivery bounces before a human hears a note.[/COLOR][/SIZE] Both figures are measured to ITU-R BS. 1770-4, so the meter you trust matters as much as the number you hit. Note the wording too. Apple says the value should not exceed the target, which makes -18 a ceiling rather than a goal, and quieter masters pass while louder ones do not. That distinction catches people who arrive from stereo mastering, where louder has been the reflex for twenty years. Getting a compliant file out the door starts much earlier than the meter, because [B][URL='https://goldmidi.com/community/threads/most-daws-still-fight-you-over-multichannel-routing.75948/']the format ceiling your host imposes[/URL][/B] decides whether you can author a legitimate immersive master at all. [HEADING=2]Upmixed masters get rejected on sight[/HEADING] The eligibility rules are stricter than the technical ones. Atmos files generated automatically or algorithmically from a stereo master are not allowed, and Apple rejects them outright. Upmixing 5.1 to 7.1 is banned on the same grounds. DistroKid rejects non-compliant files without charging for the attempt, which is a small mercy and a reminder that the first gate is automated. De-mixing is banned as well, meaning you cannot run a finished stereo release through a stem separator and call the output multitrack material. Deliverables have to originate from actual multitracks, or from stems built out of those multitracks. The practical consequence lands hard on older catalog. If the session files are gone, there is no legal route to an immersive version of that recording, whatever the separation tools can now pull out of a two-track bounce. Producers sitting on a decade of finished work tend to discover this the week a label asks for spatial versions. [HEADING=2]Sync tolerances are tighter than people expect[/HEADING] The Atmos master has to be conformed and synced to the original stereo reference, and the durations must land within 50 milliseconds of each other. That is not a courtesy alignment. It is a pass or fail check. Gapless albums get stricter treatment again. Every track boundary must sit within half a frame of the same boundary in the stereo deliverable, which works out at 1,000 samples at 48 kHz. Fades and top-and-tail trims that felt harmless in the stereo session will break this quietly Frame rate consistency applies across the whole project, and every track on an album should share one. DistroKid asks for 24 fps timecode on the ADM specifically. Only one stereo source and one immersive source are permitted per track, so there is no delivering two candidate mixes and letting the platform choose. [HEADING=2]The metadata around the file trips people up[/HEADING] [B]A Broadcast Wave master carrying object metadata[/B] is only part of what the renderer hands you. A stereo fallback, a 5.1 re-render, and a binaural re-render come out alongside it, and different distributors want different combinations of those files, so check the intake requirements before you close the session rather than after Apple also requires a unique secondary ISRC for every Dolby Atmos submission. The immersive version counts as a distinct recording in the registry, separate from the stereo one, which matters for reporting and royalties further down the chain. Reusing the stereo ISRC is a common first-timer error, and it is an easy one to avoid once you know the rule exists. Apple accepts 5.1 and 7.1 surround as a separate immersive profile too, delivered as LPCM inside a .mov container with correct channel assignments, at 48 kHz and either 16-bit or 24-bit. The same loudness and true peak limits apply to those files. One compliant master travels a long way. An ADM delivered through DistroKid reaches Apple Music, TIDAL, and Amazon on supported devices, which is why these specifications read as universal rather than as one platform's private list. One content rule sits outside all the container specifications. Full-frequency material is not permitted in the LFE channel, so routing a complete kick drum or a full bass part down there puts the file out of spec no matter how good it sounds in your room. The LFE exists for low-frequency effects; platforms check what is in it, and a bass part that needs to be felt belongs in the main channels, with the subwoofer picking it up through bass management instead. [/QUOTE]

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