Okay, my fix for s7 edge:
First you need to copy some files BEFORE flashing anything, paste them to SD card or somewhere you can find them the files you need to copy:
System/lib/hw/ audio.a2dp.default.so
System/lib64/hw/ audio.a2dp.default.so
System/sec/floating_feature.xml
Also make a backup of your wifi passwords, they will be erased
Now go to
https://forum.xda-developers.com/galaxy-s8/themes/module-dolby-atmos-s8-t3869236/page2
And find the download (all credits to Electric1447)
Download it and flash with magisk
Now it should work already, but bluetooth audio doesn't work and there are a few s9/s8 things.
Now put back all the files that you copied where they belong.
Go to floating feature and add:
<SEC_FLOATING_FEATURE_MMFW_SUPPORT_DOLBY_AUDIO>TRUE</SEC_FLOATING_FEATURE_MMFW_SUPPORT_DOLBY_AUDIO>
<SEC_FLOATING_FEATURE_AUDIO_SUPPORT_PSEUDO_DUAL_SPEAKER>TRUE</SEC_FLOATING_FEATURE_AUDIO_SUPPORT_PSEUDO_DUAL_SPEAKER>
Also in the 6th line you need to change soundalive version from 40 to 52
Flaws:
-wifi password will be erased so make sure you make a backup via Samsung cloud
- I am not sure if it's this mod but my battery life isn't that great anymore
- audio seems to be noisy if you listen closely, I think this is because of the sound booster 810
Optional:
I am using the latest soundalive from apkmirror, this adds game mode to Dolby