Trying to resolve this issue I've been having and not 100% sure of the culprit but willing to try some inexpensive options to sor it out.
Current setup is fairly basic.
Sony Bravia X700D
Onkyo HT-R390 receiver
40ft Monoprice HDMI cable
Primary media consumption is all on the TV itself using its own apps. Full use of HDMI-CEC and ARC back to the receiver. All I have on the other end of the receiver is a Steam Link with low use and a Dreamcast going through a VGA-HDMI adapter.
What I am running into is that no matter the application on the TV it will drop the audio out for a brief moment every so often. Hard to nail down the exact interval. This is on everything from Live Channels (pulls in HDHomeRun Prime channels, bit-streams audio), Plex, Netflix, and Amazon. The Steam Link and Dreamcast are flawless however and are going straight to the AVR.
My first thought is possibly a marginal signal on the HDMI cable. Considered trying to get an HDMI extender but not having any luck finding a device that is confirmed to be compatible with CEC/ARC. Optical audio is also an option but would need an equally long cable. The 40ft HDMI has about 1-2ft of slack and the only other routing option is straight down the middle of a high traffic floor.
Getting an alternative source device is also problematic:
a) I prefer Android TV devices. That limits me to basically the Shield TV and the Mi Box for 4k. The former is prohibitively expensive.
b) The AVR is also 1080p only, requiring an upgrade if going to a 4k media player.