Hi @kitt,
Thanks for the extra detail, the note about DTS-in-FLAC working while 5.1 LPCM doesn’t turned out to be a useful clue.
Your logs give a clear answer, and nothing is wrong with your Roon settings.
What’s happening: the Sony appears on your Mac as an HDMI audio device, and macOS keeps changing what it says that device can do. Roon reads the channel count each time the device reappears, and over the past week it alternated between “8 channels” and “2 channels only”, about four readings in five came back as 2-channel. We can watch it happen in yesterday’s logs: at 13:22 the device reported 8 channels, you selected 5.1, and Roon genuinely opened the output at 96kHz/24-bit/6 channels. Ninety seconds later the device reported 2 channels again and the setting greyed out.
Why the audio path still showed 6Ch: macOS publishes two format lists for an HDMI output, a “virtual” one it will always accept, and a “physical” one describing what actually goes down the cable. On your Mac the virtual list claims 8 channels at all times, even while the physical link is stereo. When they disagree, macOS quietly folds 6 channels down to the 2-channel link, so Roon sees its stream accepted while your receiver only gets LPCM 2.0. We’re raising that mismatch internally.
Why your setting vanished: on 16 September the Mac changed the internal ID of that HDMI output. Roon treats a new ID as a new endpoint with default settings, which is why the 5.1 configuration didn’t carry over.
Worth knowing: with the TV off the output appears as SONY AVSYSTEM; with it on, as LG TV SSCR2. Those are two separate endpoints with independent settings, so the channel layout has to be set on each.
What to check: the root problem is HDMI-side, that output disconnects and reconnects 15–20 times a day in your logs, sometimes twice within ten seconds.
- With Roon idle, open Audio MIDI Setup and check the Sony’s format list. If it only offers 2ch there, the Mac isn’t seeing multichannel and Roon can only follow.
- Turn off Control for HDMI / Bravia Sync (CEC) on the TA-AN-1000 and let us know if the dropouts stop, CEC handshakes are the usual cause.
- Check the HDMI Signal Format setting (Enhanced vs Standard) on the input Roon uses.
- Failing that, try a different cable and input.
Once the output stops disappearing and reports 8 channels consistently, 5.1 should stay selectable, and the six channels will actually reach the receiver instead of being folded down on the way.
Let us know how the CEC test goes.
