We have two windows computers in our kitchen. For a while now they have been set up so that you have to plug the one you want working right now into the external speakers. Today I finally looked into a better way. Turns out there is a free one, or free as long as you already have a male-to-male audio cable.
Plug one PC’s audio out into the second PC’s audio in. On the second PC (Windows 10), go into control panel, Change sound card settings, recording, pick the plug you used, and click properties. Click the “listen” tab and check “listen to this device”. I had to set the levels way down to 5/100 to not get any distortion and just get a full volume output from the first PC.
No more plugging around!