Google Home owners have been clamoring for years for an option to set up speaker pairs to get stereo sound. The feature rolled out to the Home Max, Insignia's cheap Assistant speakers, and the new Nest Mini, but Google's original Home and Home Mini were left out. Now, the feature is available on both.
To set up a speaker pair, head over to the Google Home app, tap on one of the speakers you want to pair, then the settings cog in the top right. Scroll down and look for Speaker pair (is should be below Night mode). Tapping it starts the process and asks you to choose which units you want to pair, pick a left and right channel, then assign a name, home, and room to the joined speakers.
When you're done, the pair shows up as one speaker in the Google Home app and across all your Chromecast apps and targets. Stereo sound separation is properly done too. You can verify it by playing Moving in Stereo by The Cars, a song that has very distinct left and right channels.
Music, controls, volume, everything works on both speakers in tandem. Even if you manually raise the volume on one, the other follows suit. Their settings are linked in the Home app too, so enabling night mode or joining the preview program is an all-or-nothing affair. You can still reboot them separately, though, and change the sound's balance between left and right channel. Oh and they can be added, together, to a larger speaker group.
If you test this setup and prefer to have two separate mono speakers, you can always separate the pair in the app.
One last thing you need to be aware of is that to avoid Assistant issues with both speakers in the same room, always-on listening gets disabled on the right channel and only the left one lights up and hears your Ok Google commands.
Speaker pairing is available to us on both Google Homes and Home Minis, and doesn't seem to be linked to a server-side test or a preview firmware. If you have a dozen Home Minis from all those free promos over the past year, now's the time to make the best of them.