[Rasplex 1.7.1] Rasplex won't let 7.1 passthrough, automatic downgrade to 5.1



Hey guys,

I'm struggling with an issue with my audio set up.

My set up is as follow : NAS Synology with PMS --- Rasplex 1.7 --- Sony RVX465 amplifier --- Sony MDR-HW700DS --- TV

My audio configuration in Rasplex is : 7.1, passthrough, AC3, DTS enabled, output configuration optimized or best match.

The issue : When I'm reading a 7.1 DTS file, I have my AC receiver and my headphone receiver showing that the received audio track is DTS 5.1.

What I already did to troubleshoot this:
-Skip the Sony RVX amplifier, directly connected to Sony MDR it is shown as 5.1. --> Not the AC receiver issue
- If I play the same file from my Mac to the AC receiver, both the Sony MDR and RVX amplifier show the audio track as DTS 7.1 --> Not an audio track issue
- If I set up the output configuration to "Fixed", then it is well shown as DTS 7.1... even when I read 5.1 track...

I really don't understand why Rasplex does not allow a real passthrough audio.

If you have any guidance to troubleshoot this, it will be much appreciated !

Thanks in advance!

PS : same issue with Rasplex 1.8

The audio track info from Plex:
Codec DCA
Chaînes 7.1
Langue English
Audio Channel Layout 7.1
Bit Depth 24
Bitrate Mode VBR
Durée 2:21:37
Profile ma
Sampling Rate 48000 Hz