Add me to the list… Went from Arc, Sub Gen 3 and Era 100s to Arc Utlra.  Atmos is amazing, but any 5.1 content sends the surround content to the Ultra outside surround speakers, with hardly any content to the rear Era 100s. I used DB meters, test files etc.

While this may work OK in a small room with a low ceiling, it fails miserably in my large living with a vaulted ceiling.  I would think it could be fixed with application logic or a firmware fix, but for now I sent my UItra back and will stay with the Arc. If it is ever reported here that it is fixed, I will revisit, but I cant see losing surround experience for $1000, especially when the actual sound quality is so close between the Arc and the Arc Ultra.

I have the same problem here with the Arc Ultra and the Era 100 as the rear speaker. With Dolby Atmos content, everything sounds great, but with Dolby 5.1, the Era 100 does produce sound, but not specifically for the sound source.

Is there a statement from Sonos as to when a solution to this problem can be expected? It can't be that they throw their “flagship” onto the market and that it doesn't even work with their own products! Embarrassing!

In the meantime, I'm really annoyed. Nobody believed us at the beginning, I spent days testing afterwards to narrow down the error. It was only a few weeks after the product was released that the problem was finally confirmed, before that they tried everything to blame the problem on our side. That makes me sick. This kind of testing should take place BEFORE the PRODUCT RELEASE by Sonos. Now we are being stalled again and have no idea how long it will take to fix this serious problem: Days, weeks or even months? After all these days of wasted time, Sonos should simply replace the Era 100 rearspeakers with properly functioning Era 300s for real surround sound. That's how much my days of testing would be worth and would be a nice gesture of compensation. At the moment I'm really annoyed that my old cheap Beam Gen 2 had much better surround sound with the Era 100 rearspeakers. I mainly stream series with 5.1 sound 99% of the time. The return period for the Arc Ultra has already expired. I was a big Sonos fan and was really proud to be one of the first to own the Arc Ultra. Now I'm just disappointed.

Hi Zorro88, 

I’ve just registered to make this comment.

I’ve been in contact with ‘support’ and they originally said they would look at this and hope to implement a fix before the end of this year. They have just been fobbing me off saying this will be looked at with no promise of a resolution timeline…

Sonos promised us products would be tested before they go on sale but it looks like this was missed intentionally.

I hope the fix comes soon as my era 300’s are only using the outer channels (side rears), not both the side rears and rear, rears if that makes sense?. The Ultra side drivers are playing at the same time as the rears as well.

Both front and rear heights play regardless, it’s just a mess.

Shame on Sonos…

Anyone tried the new update yet? Does not seem the DSP is altered. Maybe we can notice any difference after applying Trueplay again?

https://support.sonos.com/en-gb/article/release-notes-sonos-system-updates
Current system version: 82.2-59204

I have just tested it, no change regarding the 5.1 soundtrack issue. Channel 4 and 5 still playing at the front.

Let's hope they fix the issue Q1 2025…. don't expect another update this year.

Same here. No change. I understand the real beta test is when a product hits the streets, but timely resolve would go a long way to repairing their damaged reputation, especially from the app side…. of course, the suspicious side of me is almost expecting the “Ultra Era Surround” line that you will need to buy for a correct surround experience with the Ultra Arc… but that’s just me

Same here no change 

But does anybody care?

No improvements with the latest update. Sonos are fully aware of this and chose to release the product regardless.

My old Arc worked much better with channel separation. When it’s sorted, the arc ultra will be better than the arc. It’s just a shame they released their flagship product and blatantly when back on their promise as they thought people wouldn’t notice.