Hi,

I’m looking at upgrading to the Era 300s for rear surrounds. I know that currently the center driver is disabled when used in this configuration.

However, I spent quite awhile on the phone with Sonos support in the weeks after the Era launch trying to understand how the remainder of the drivers work (as surrounds) with various content. What I was told by Sonos support is starkly different from what I’m seeing posted on places like Sonos sub on Reddit.

As a quick fact, some 5.1 content is mastered as 2Front 1Center 2Surround (side) LFE while others choose 2Front 1Center 2Rear LFE. This was the breakdown Sonos support gave as to how each audio format should be handled by the Era 300 (as rear surrounds):
 

* Stereo content should be spread across the entire stereo field. So the center driver on the soundbar will be playing the centermost content on the spectrum while the drivers on the L (so all the drivers on the left of the soundbar plus the dual drivers inside & outside on the Era 300 as well as the upward firing driver) together all make up the remainder of the L stereo channel and will play the content where it should be in space (obviously, the opposite holds true for the R side).
* 5.1 content uses both dual inside and outside drivers together along with the upward firing driver for the surround or rear channels (whichever was chosen when mastering).
* 5.1 Atmos uses both dual inside and outside drivers together for the surround or rear channels (whichever was chosen when mastering) while the upward firing driver handles the Atmos height effects.
* 7.1 uses the outer two drivers for the side channels, and the inner two drivers combined with the upward firing drivers for the rear channels.
* 7.1 Atmos being the most straightforward of all with outer two driver handling side surround, inner two drivers handling rear surround, and the upward firing driver handling heights.

​​​​​​​So, regardless of which of these mastering methods were chosen (whether surrounds were setup as side or rear surrounds), all of the drivers (except the known center) would play the (rear or side surround) audio data. So, this would mean that the surround channels will be heard in both the inside and outside dual drivers as well as the height. This made sense to me as the most reasonable choice. Otherwise, on 5.1 content (which is still a LOT of content) only the outer two OR the inner two would be working (depending on master choice) - and in both cases 4 of the 6 drivers would be doing nothing. This would make the Era 300 a massive waste for much of rear surround listening. In fact, a lot of streaming services that support Atmos still only support 5.1 Atmos. That would still mean that only the outer or inner two driver were used with the Atmos effects being played on the upward firing drivers, even on streaming Atmos content, half of the Era 300 drivers would be unused.

I was assured by Sonos support that if people’s systems were only playing in inside or outside two drivers on 5.1 content, that it was a bug and they should reach out to support.

So, all of this background info to ask:
​​​​​​​* Is the above how the Era 300s should work as surrounds? Did Sonos support give the correct info at that time and have there been any changes at all in how this works with subsequent software updates?
* Is this how do the Era 300s actually work in the real world when used as rear surrounds in people’s Sonos systems? (Are you hearing 5.1 content across the inside/outside/upward firing drivers? Are there Era 300 drivers used when playing stereo? Or are you only hearing it from the inside or outside two drivers?)

I’m really hoping for some definitive info on this as hearing conflicting info on user forums is just confusing, at best. I’d be disappointed to spend the additional $$ on the Era 300 only to find that in real world use, half the drivers (or less, depending on the source) are actually used. I thought that what makes the Era 300s magical is the fact that they use all those drivers to give a greater immersion bubble - even on 5.1 content. Thanks so much!