Arc and Arc Ultra Not Connecting to Era 300s and Subs

Have you tried something as simple as resetting your router?
So not just a restart, but a complete reset.

Hardware

• Asus Router (GT-AXE16000)
• Sonos Living Room Soundbar (Arc Ultra)
• Sonos Living Room Right (Era 300)
• Sonos Living Room Left (Era 300)
• Sonos Living Room Sub (Sub)

Steps

1. Ensure Airtime Fairness is disabled across all bands through Asus Router: Completed
2. Ensure DHCP-PD is enabled for IPv6: Completed
3. Forcebooted all Sonos devices: 
4. Connect Living Room Soundbar through Sonos App: Success, device connected to Sonos network and wireless network
5. Connect Living Room Sub through Sonos App: Success, device connected to Sonos network and wireless network
6. Connect Living Room Left through Sonos App: Success with deviation, device could not inherently find connected network, but manual entry allowed connection. Device connected to Sonos network and wireless network
7. Connect Living Room Right through Sonos App: Success, device connected to Sonos network and wireless network
8. Rename Living Room Right and Living Room Left through the Sonos app accordingly to better identify through the app.
9. Attempt to play music through Living Room Soundbar: Success, music plays fine
10. Attempt to play music through Living Room Right: Success, music plays fine
11. Attempt to play music through Living Room Left: Success, music plays fine
12. Matched IP Addresses using Router UI and Sonos>General Settings>About Your System
    1. Living Room Soundbar: 192.168.50.9
    2. Living Room Right: 192.168.50.233
    3. Living Room Left: 192.168.50.28
    4. Living Room Sub: 192.168.50.117
13. Confirm all IP addresses are assigned through DHCP: Success, none are associated static.
    
    ***NOTE*** At this time, prior to synchronization attempts, I have confirmed all devices are connected to the Sonos app successfully, and are connected/assigned IP addresses through the router dynamically. Except for the sub, I’ve confirmed all devices are able to operate/play music independently. I have confirmed during the setup that the sub is emitting noise. All devices are operational and 
     
14. Connect Surround Sound Speakers to Ultra through Ultra UI (Living Room Left & Living Room Right): Unsuccessful, Living Room Right connected fine, but Living Room Left didn’t connect.
    1. During setup, I used the in-app test to confirm that both speakers emitted sound prior to selecting them.
    2. The app asked me to align each speaker to the main room.
    3. The app asked me to identify the speaker emitting a tone, to which I selected the Living Room Right speaker
15. Find Living Room Right in router: Successful, Living Room Right maintained DHCP IP address.
16. Find Living Room Left in router: Unsuccessful, Living Room Left no longer appears in the list.
17. Forceboot Living Room Left, reconnect through Sonos, and reconnect through Ultra UI (Remove speaker allowed for the left speaker alone to be reconnected): Unsuccessful, Living Room Left repeated failed connection
18. Forceboot both Living Room Left and Living Room Right, and reconnect through Ultra UI: Unsuccessful, neither speaker connects.
19. Repeat Step 14: Unsuccessful, neither speaker connected this time.
20. Connect Living Room Sub to Ultra through Sub UI: Unsuccessful
21. Forceboot Living Room Sub: Unsuccessful, during initialization with Sonos, when holding device to speaker, Sonos reports “New tag collected: 
22. Connect Living Room Sub through Ultra UI: Unsuccessful, device shows in Ultra software, but it doesn’t play at all, even though it emitted noise prior to initializing setup.
23. Forceboot both Living Room Left and Living Room Right, reconnect through Sonos: Successful, both speakers reconnect back to the system.
24. Connect Living Room Left and Living Room Right to each other as a Stereo: Successful, speakers connect to each other just fine.
25. Connect Living Room Sub with Living Room Left/Right Stereo: Successful, sub connects.
26. Validate Router: One IP address is acquired for the group in router, all devices are successfully synchronized in the app, and all devices are connected when playing music
27. Forceboot Living Room Right, Living Room Left, and Living Room Sub, and reconnect all devices through Sonos: Successful, all devices successfully reconnected and playing music again.
28. Connect Living Room Sub through Ultra UI: Unsuccessful, sub not showing.
    1. ***NOTE: After multiple attempts of this, when adding the sub, the LED indicator alternates between a few states.
       Standard: Soft White
       Connecting: Hard Blinking White
       Disconnected: Soft White that blinks orange when the button is pressed
    2. During initialization, it goes into two phases of Connecting (each lasting 32.5 seconds) and switches to Disconnected, even as the app is attempting to connect.
29. Connect Living Room Left/Right through Ultra UI: Unsuccessful, devices not showing.

Suspected Outcome

The code that is executed when connecting devices through the Sonos app ONLY FOR THE ULTRA (both from the Ultra UI and device UI) intermittently sets them in the correct state with approximate 5-10% success rate of visibility and a 75% chance rate of true connection (output successfully synchronized).

If there was an obstacle with DHCP with my router, I should not have been able to connect the left/right/sub together as a zone, yet that was successful 100% of the multiple times I attempted to connect it.

I’ve reattempted the above steps with a second set of devices altogether with same outcomes (Game Room). Both of these zones use the same setup (Arc Ultra, 2x Era 300’s, and Sub), and both of them began encountering these errors at the exact same time (on/around 5 May 2025).

There are two possibilities based on my observations:

1. There is an issue with the code that executes when synchronizing devices only to the Arc Ultra that is causing disconnect 90-95% of the time, and it roughly happens 32.5 seconds into the connection process for all devices. I’ve had more success connecting the Era 300 speakers, though when it attempts to connect both speakers at the same time, each speaker rolls probability independently.
2. The Arc Ultra firmware is not equipped to provide consistent connection to all devices like the Era 300’s could be set up.

Either way, the software and firmware around the Arc Ultra needs to be evaluated for changes that rolled out to production in early May.

Yes, I have to no success. This was a last-resort option for me, as I have MANY devices that needed to be reconnected.

I am struggling with believing that my router is the problem here, as I’m able to make another speaker (specifically an Era 300) as a master device without issue.

Can you help me understand why other devices in the Sonos system can establish parent/child relationships through the native app software, but the Arc Ultra specifically is incapable?

I do not believe you can make the Era 300 the “parent” to another speaker in the same way a Sonos soundbar will be parent to surrounds. The soundbar uses a dedicated 5Ghz link and the relaying thing for this. I suppose you can only group the Era 300, and then it is only a group coordinator on 2.4Ghz, that is totally different.

Hi ​@antman1978 

​@106rallye is completely correct - a Home Theatre bonding operates completely different than a stereo pair or a Sub bonded to one speaker or a pair. With the former, the satellite speakers connect to the Home Theatre primary (the Arc Ultra), whereas with the latter, they still connect to the router. The HT setup is specifically for low latency and staying in step with the TV picture.

In addition, it is only during playback that the satellites connect to the HT primary - when there is no playback, they will switch to connecting to the router via 2.4GHz to save power. So, the only time the satellites try to connect via the Arc is during playback, and that is when they will fail due to the router’s refusal to allow it.

I hope this helps you understand why it seems illogical at first.

I’m beginning to understand it. 

I’m still confused why the soundbar had a low success rate with connecting speakers and why the speakers that do connect seem to work intermittently if the router is refusing to allow the satellites to connect via the Ultra Arc.

I’m also still confused why plugging the Ultra Arc in through ethernet overrides the routers refusal to allow these satellites to connect through it when the Arc itself is the only device actively hardwired in.

These are both questions for your router manufacturer.  99% of routers have no problem with the configuration of surrounds in Sonos. 

Hi ​@antman1978 

I am not sure I can help with that - a little above my pay-grade, to be honest. Though, I understood your report to be saying that you could not get any audio from the surrounds, when they were configured as surrounds. You mentioned adding one surround at a time and each one playing, but you could only have added them to the system, and perhaps put them in a room also called Living Room, but you could not have added one surround speaker and tested it - that is impossible. As far as I can tell, your report is entirely consistent with a router refusing to perform DHCP Proxy services.

My guess - in regards to the Ethernet connection - would be that your router considers that more secure. Again - just a guess. As ​@jgatie mentions, you would have to ask the manufacturer.

I hope this helps.