[c.grex]

@cgrex What hardware do you have? What receiver? How is the MiBox connected to the receiver (ie directly or via TV)?

Sony str dh800 receiver - doesn't support 4K, but does support HD-Audio (Dolby True-HD & DTS-Master)
Samsung JU6400 4K TV.

Mi Box (Model MDZ-16-AB) HDMI > Sony AV HDMI > Samsung

Kodi 17 Allow Passthrough and 'Passthrough output device - android, audiotrack' is grayed out
With this I get no sound on my AV at all.

SPMC Allow Passthrough and 'Passthrough output device - android, IEC Passthrough' is now selected.
With these settings I get AV receiver showing that it is 7.1 DTS Master Audio, but the sound is just a series of pops.

Kodi krypton and version 6.01 MHC19J 750

The same files passed through ok on a shield.

I would imagine you have checked Android Audio settings and made sure HDMI only Audio is selected ?

Android set to HDMI audio

these are the test files (for anyone else that wants to try):
DTS HD Master
http://www.filedropper.com/71chdts-hdma-...ngtestfile

Dolby TrueHD
http://www.filedropper.com/71chdolbytrue...ngtestfile

I am guessing that the Mi Box will do pass-through for HD Audio but it is limited on the bit rate of the file. I also have a 30GB BluRay rip with MA audio that I can't get any passthrough but that works fine on a shield ( I borrowed the shield before buying mi box). So looking like a shield is the only way I'm going to get the Full HD audio passthrough I want! just at £190 it's a big jump!