Home Theater system

Chipsets that handle ‘all’ the frequencies are probably twice (or more) the cost, and in aggregate, it likely is cheaper to run two lines. 

I think the WiFi argument was used by Sonos on this community when someone with a mixed set up had the same complaint as OP. Since the search function on the community seems to actively prohibit a user finding anything worthwhile, I did not bother looking for the thread.

A quick look at WiFi modules didn’t find any that didn’t support the full frequency range within each band, they leave disabling the frequencies/channels not allowed to be used to the containing device manufacturer.

Can’t do it on Sonos of course but on my Linux devices I can load a module control driver that allows me to select any of the channels. I do get a pop-up warning if I pick one not universally available.

https://en.wikipedia.org/wiki/List_of_WLAN_channels

For 2.4 gHz there are channels 1 to 14 available, 12, 13 are restricted in the US and usually not enabled to ease device certification, 14 is not allowed.

For 5 gHz there are channels 32 to 177 available, 52 to 144 are under DFS restrictions, 169 to 177 are restricted to indoor use only, within set limits.

I’m not finding specifics but I seem to recall Support was supposed to be able to do something remotely to assist folks with region issues.

The forum search AI is helpful: (as are the links it provides here)

AI Answers

Summary about “region” on Sonos

• Sonos devices and services can be affected by region settings and regional differences in radio/channel availability, which can cause cross‑region incompatibilities between devices (for example, US vs EU device channels) (cross-region compatibility).
• Snipped non radio text
• There are community discussions and guidance about setting the Wi‑Fi/region for Sonos devices if needing to adjust regional settings for functionality (Setting the WiFi region).

Note: The documentation provides partial information on this topic.

If one Era 300 works on its own but goes silent when added as a surround, the first thing I'd check is whether both surrounds are properly assigned as a stereo pair and bonded to the Arc Ultra in the Sonos app. Also try removing the surround setup completely and re-adding both Era 300s from scratch — Sonos occasionally gets confused during the bonding process, especially after firmware updates.

Uhhhh, no.  Surrounds should not be “assigned as a stereo pair”.  In fact, if they are stereo paired, you need to separate the pair before they can be bonded as surrounds.

Are people reading this thread? While opinions are appreciated you should Read the Best Answer rather than commenting on the latest post 😂