I have gone through this forum without a definitive answer around the last 2 years. When I play movies in MKV containers with 5.1 audio, i sounds fine through plex app on PS4 Pro.
However, when I play back an MP4 container with AAC 5.1, the sound is terrible.
I have an AV receiver connected in between the PS4 and the TV that can do 7.1 but only have 2 speakers and a SubWoofer connected. I have set the PS4 Pro to HDMI out and 5.1 Audio while the AV receiver is set to Auto set the audio and detects the 5.1 stream.
In Plex, I have set the 5.1 Audio settings as well.
Can someone please help me understand why this is happening and how to possible fix it?