I am thinking of getting a Streambar for a small bedroom and use it for audio only. My idea is to mostly cast Spotify to it, but I have heard that it will not work without a display plugged in and turned on. I am also considering plugging in a blu-ray player via HDMI to play CDs. Would this work? I know the intention is for the HDMI to be used with a TV's HDMI ARC, so would it work to have a device inputting audio directly over HDMI?
For the first question, I've used an "HDMI Dummy Plug" like this to experiment with my Streambar and I believe it would work for what you want to do. I was going to do something similar for playing music, but I never got around to setting the whole thing up. I was able to connect the dummy plug and then blindly navigate to my music app and get it to play, but I didn't try casting. I don't see why it wouldn't work. There was also a similar question regarding turning off the TV and keeping the Streambar from stopping whatever it was doing and returning to the Home Screen. I believe a powered HDMI switch worked in that case.
Using the audio return channel sounds interesting for connecting another device, but I would think it requires some kind of adapter. I don't know if such a thing exists. I don't think connecting the Blu-ray player's output directly to the HDMI output of the Streambar is going to work and I'd be a little afraid to try connecting two outputs together. You could get an HDMI audio extractor that has an optical output and connect to the Streambar via its optical input.
