Can you not set up your HomePods in the
Home app like in Apples own instructions for using them as a stereo pair?
Create A HomePod Stereo Pair
Here's what you need
Set up a HomePod stereo pair
When you
set up a second HomePod in the same room as another HomePod, you'll see an option during setup to use both speakers as a stereo pair. You can also set up a stereo pair with two HomePod speakers in the Home app on your iPhone, iPad, iPod touch, or Mac.
On your iPhone, iPad, or iPod touch
- Make sure that both HomePod speakers are in the same room in the Home app.
- Open the Home app, press and hold HomePod, then tap Settings.
- Tap Create Stereo Pair.
- Choose a second HomePod to use as a stereo pair.
- Tap a HomePod on the right or left side to identify it. Tap
to swap them to the correct left and right channel.
- Tap Back, then tap Done.
On your Mac
- Make sure that both HomePod speakers are in the same room in the Home app.
- Open the Home app, double-click HomePod, then click Settings in the upper-right corner.
- Scroll down and click Create Stereo Pair.
- Choose a second HomePod to use as a stereo pair.
- Click a HomePod on the right or left side to identify it. Click
to swap them to the correct left and right channel.
- Click Back, then click Done.
After you complete the setup, the option to select your HomePods in theory would now be in the audio options/menubar dropdown? My AirPlay devices are in the dropdown for the speakers on my iMac, I can choose any one of those as the audio source for the computer. I don't have HomePods myself, but it seems this should be pretty straightforward.