jjdolbypro (Customer) asked a question.
Any tips for Apple vs Dolby headphone consistency?
To my ears, Apple kills some of the reverb and replaces it with their own generic room sound. Most songs that are available in Atmos on both Apple and Amazon sound different. Bohemian Rhapsody sounds practically identical. So either it's possible and there's a method to it, or maybe Queen's engineers delivered separate Atmos mixes? I'm sure it's possible if you're a major label repping a legendary artist. I've seen big labels do things on youtube that mere mortals like me can't, like replace old videos with 4k versions without losing views, likes or comments.
Apple uses the DDPJOC codec which doesn't use the binaural render mode distance metadata. Instead it decodes and renders the audio to 7.1.4 ahead of Apple's proprietary Spatial Audio binauralization process. Amazon Music uses the AC4-IMS codec which does use the binaural renderr mode distance metadata. Depending on the content and the distance settings used this can indeed lead to discrepancies in how content sounds on headphones on the two platforms. Conversely sometimes the differences are minimal. I'm not aware of instances of different masters submitted.
It might be a good idea to work with a tool like the AudioMovers product (https://audiomovers.com/binaural-renderer-for-apple-music/ ) to allow for A/B switching. This functionality to emulate Apple Spatial audio while mixing is also present in Logic Pro.
Best,
Adam