ARC-in-only speakers / ARC-video splitter?

[gjspambucket]

I ordered a Sonos Beam and found out it only takes HDMI-arc in... I do all my TV and movies with a media-center PC. It would be fine to have all the HDMI go in to the TV, and have that go to the speaker, but then I can't listen to music at night with the TV off.

I think I need a box that takes HDMI in, and splits the audio out as HDMI-arc, and the video off as HDMI. I'm worried about cheap laggy electronics boxes from china -- any recommendations on something that wont cause me sync issues, works well, and hopefully isn't hundreds of dollars?

I'm open to other solutions, but a full on home theatre receiver is wayyyy overkill for my setup.

 

[americanaudiophile]

HDMI-ARC carries audio from the display back to the audio system. That won't help you even if you could convert the PC HDMI output to ARC (which you can't).
If you got a soundbar with HDMI in and out then you could run the PC through it.
Sonos assumes that when you don't use the Beam with the TV you are using IT as the source of your music not a PC.
If you want to play files on the PC you can do that with the Beam. Add them to your Sonos music library. The Sonos app supports most music streaming services too.