SWYH VS Livestream.Monitor

Never tried this but you might simply play the audio on your PC using the EQ of your choice and send the output to a UPnP renderer using http://www.streamwhatyouhear.com/

You could try Streamwhatyouhear ( https://github.com/StreamWhatYouHear/SWYH ) i still have to try it myself, but according to the documentation Sonos is supported.

However, I have read about a utility called "SWYH"/Stream What You Hear", which ought at least help with auditioning your mixes & masters in real world scenarios. Streams the output from your DAW over the internet, so you can check it out on pretty much anything that can stream audio online, and get a better idea of how your efforts are coming across.

If you are on Windows -- https://www.streamwhatyouhear.com/

Firstly, you need to install Stream What You Hear ( https://www.streamwhatyouhear.com/ ) to transmit your PC audio as a webstream. Then enable the Alexa MyMedia skill and set up a playlist to play that webstream. Finally, put an echo into a smart home device/room group, whose preferred speaker setting is set to the echo(s) you want to play on. Then ask the echo in the room group to ask MyMedia to play that playlist and, after a short delay as it buffers, your PC audio should play on the preferred echo(s). You might be able to set that request up in a routine with a customised action to run on the room echo so that you can trigger it from the Alexa app directly.

The closest I've seen is SWYH ( Stream What You Hear ) which I haven't managed to get working.. yet (I haven't put much time in it).

Not as straightforward as you might think. There are a couple of things I can think of but SWYH may be best for your case: https://github.com/StreamWhatYouHear/SWYH

Twitch seems to spend most of its development resources on countering ad-blockers. I gave up and went with Streamlink, mpv, and Livestream Monitor.