Problem with monitoring through prosumer receiver

[V5V]

Anyone here know anything about the Denon DN-A7100 receiver? It's an older A/V receiver that has balanced XLR outputs instead of internal amplifiers. Input is HDMI.

I have a 2016 MacBook Pro Touchbar. Connected to one of the USB-C ports is an adapter that provides HDMI output, USB-A (for the iLok), gigabit ethernet and power pass-through.

When I connect the HDMI port on this adapter to HDMI input on the "conventional" home theatre receiver in my living room, everything works as expected. I can output a surround mix from Pro Tools using the Playback Engine for that port (it shows up as "Displayport" in Pro Tools) and everything comes out of the correct speaker.

When I take exactly the same setup and plug into the Denon DN-A7100 instead, I get the Left and Right channels but nothing else.

I've configured it in the Mac Audio/MIDI setup utility. The channel numbers going to the speakers correspond to SMPTE 5.1 output (L/R/C/LFE/Ls/Rs). The volume faders for the eight channels are greyed out, but I assume that's because the Mac doesn't control the level through HDMI/Displayport. I've chosen the 8-channel 48K 24 bit option.

I tried playing an iTunes movie with VLC just to see what would happen and got the same result. With a 5.1 audio track selected there was no dialog because I was only getting the L & R, no centre (and no surrounds or sub)!

Because the receiver is about ten years old it only supports HDMI 1.1, but I can't imagine that being an issue since audio-only playback doesn't require any of the capabilities of later versions.

Operating system is 10.12.4. Pro Tools is 12.7.1. I don't think either of those is relevant though, since it works with my cheap living room system. The problem would then seem to be with the Denon.

Any suggestions are gratefully appreciated!

[DetroitT]

Reflecting thought;

What is the "conventional" home theatre receiver"?

Check with Denon for firmware upgrades.

[V5V]

Originally Posted by DetroitT

What is the "conventional" home theatre receiver"?

The living room receiver is, coincidentally, also a Denon, model AVR591. I selected it on the basis of two very important criteria:

1. It was inexpensive.
2. It's shallow enough to fit in the small space available in the living room!

Even though they're both Denon, neither receiver was chosen based on the brand. It just worked out that way by coincidence.

Originally Posted by DetroitT

Check with Denon for firmware upgrades.

I'lll keep looking, but so far I haven't been able to find anything, presumably because the unit is so old it's fallen off the support map.

I sent a message to Denon technical support with the same information as what's in my original post here, but I'm not holding my breath that anyone there has been around long enough to even remember this model! In consumer electronics, ten years might as well be a century.