The Play 5 (gen 1) is S1 only. Are you using the S1 controller?

Does your iPhone use USB-C or Ligtning as a connector?

Hi! I’m sorry I’m not sure what an S1 controller is? I’m new to Sonos. I’ve just the Play 5 Gen 1 speaker itself. As far as the connector. We are using the lightning but also we have a USB-c iPhone 16 phone new to the family :)

And thank you for your reply 

There’s an Apple adapter that takes USB C to 3.5mm headphone jacks, which you could then plug a cable in to that goes to the line in on the Sonos. You’d want to set the volume on the phone to around 50% at least, I think, as this is a kludge, and the Sonos is expecting a line level signal, not the variable signal provided by the phone. 

The PLAY:5 gen 1 really is an ‘ancient’ device, relatively speaking. You’ll need to use the S1 controller on it, just to turn on the line in on the device, much less control the volume. I predict you’re not going to be very happy with all this. 

I’d really suggest not using music from the phone at all, but moving that music to a desktop, or NAS, and using the more normal music library function built in to Sonos S1. 

Depending on when the Play:5 Gen 1 was last used, you may need to connect it to Ethernet to get it to connect to the S1 app.  If that doesn’t work, then the firmware is way out of date and you need contact Sonos support to push an update.  After than, you need to go into the settings in the app and turn Autoplay on for the Line-In.  Then connect a 3.5 mm stereo connector from your iPhone (not sure what cable, ask Apple) to the Line-In on the Play:5.

Line-In info: 

https://support.sonos.com/en-us/article/use-line-in-on-sonos

https://support.sonos.com/en-us/article/adjust-line-in-settings