From the support desk 2026-11

How do I play my own MP3 on a Sonos speaker from an Activity?

In short

Add the file with Settings › Add Custom Media, then add the Sonos speaker's .MEDIA SET command to your Activity and type the file's name as its parameter. Roomie serves the file from your controller and Sonos plays it. The Play Audio action is different: it plays only on your Roomie controllers, never on Sonos.

Play Audio vs. Sonos

Play Audio is meant for chimes and announcements on the controllers themselves, so it plays through the iPhone, iPad, Mac, or Apple TV running Roomie. To have a Sonos speaker play the sound, send the file to the speaker with the method below.

1. Add the file

Go to Settings › Add Custom Media and pick your MP3 (or another audio file). The option appears on a controller with Full Access while a Roomie plan is active. Add the file on the controller that will run the Activity, because that's the controller Sonos fetches it from.

2. Add the command

Edit the Activity, add a command for your Sonos speaker, and choose .MEDIA SET. In the command's Parameters section, enter the file name exactly as it appears in your custom media, including the extension (for example, doorbell.mp3). Save, and run the Activity to test it.

If nothing plays

Sonos fetches the file from the controller that sent the command, over your home network. Turn on Settings › Local Network Control so the controller accepts that request. Also check that the file name matches exactly, because a typo or a missing extension is the most common mistake.

Distilled from real support conversations, with details generalized. Every setup differs — if this doesn't resolve it, contact support with diagnostics.