Yes, that’s clearly shown on the website:
 

Which generations of Sub are compatible with Arc Ultra?

All generations of Sub and Sub Mini are compatible with Arc Ultra. A dual Sub setup requires Sub 4 and/or Sub (Gen 3).

I’m surprised they took 90 minutes to tell you that though. 

Just to say sounds amazing. I haven’t noticed the sub missing! 

Congratulations on getting bent over like the rest of us that had the same plans. I returned my ultra this morning. II will never buy another Sonos product again. The company has lost its way and has become the Apple of speakers.

Besides two sub config, It can’t even do lossless from Apple Music. It’s fast becoming obsolete. 

@ravekid75 Have you considered there maybe are technical reasons for this? Have you tried using only one Sub, since the Ultra has more bas, so maybe two Subs would not be necessary? And why the disappointment? Sonos has made not secret of this.

Because I think it is completely asinine of them to not make it work. If they wanted to they could. There are many people out there like me that came from having a Playbar and purchased a Sub gen 3 when the arc came out to have dual sub setups. And to put the icing on the cake the Gen 4 is a matte finish which will look terrible if you already have a 3 in gloss. The price of used Gen 3s will go through the roof because there will be enough people with more gold chains than brains that are going to just suck it up and take it. As far as not needing a second sub, I can assure you after having a dual setup that is not an option for me. 

And now my comments are being flagged and not posted. Very classy and typical of a company that has dug themselves another hole. 

Speaking for myself, I’m disappointed that the gen2 sub I bought from Sonos is 2021 is already missing features. 

When was that gen 2 Sub designed? What hardware is in it? When did Sonos release the ability to add two Subs in a Home Theater environment, and what were the requirements at that time?

Why can’t a 3 year old sub play lossless with Apple  Music? I don’t know what hardware is in the sub but it must be some cheap ass ancient stuff, not what I expected from a premium product  

As to when it was designed and what hardware I didn’t think it mattered. Sonos stuff is usually good for a long time. I’ve learned my lesson, won’t happen again. 

The last few days the community has been inundated with spam messages. Maybe they’ve set the filters a bit too strict. Again, this is maybe not Sonos willingly double crossing you, like you seem to think.

To the point of really needing two Subs, I understand you’ve not even tried using only one Sub with the (more bass friendly) Ultra?

Just to say again. The bass sounds loads better, the one sub and ultra preforms brilliant. So not noticed not having both subs. I used the sub gen 2 and added to an old pair of ones, I have in the kitchen, which made the sound another level. Just have to hide to sub so missis doesn’t notice.

I have Arc, Era 300 as surrounds and dual sub (Gen 2 and Gen 3). By upgrading to Ultra, like you, I will not be able to use the second sub. Do you think it is still worth the upgrade in this scenario? Were you also upgrading from Arc + Era 300 + dual sub?