Mono usually sounds better when folks aren’t positioned in the stereo image sweet spot.

If you set up your Sonos as six independent Sonos Rooms and then Group them the sound will be in perfect sync.

The Play 3 has been long discontinued, you might find some on the used market but that isn’t without risk.

A current Sonos, like the Era-100 would likely do better for you.

If you add a Sub it will only connect to one Sonos Room so the other speakers will continue to play full range sound. I’m not sure how much good a single sub would do in that large space.

If you are willing to step up from a Play 3 replacement size, the Sonos Five will give you a lot more sound and wouldn’t usually require a Sub. Maybe try four and add more if needed?

I’d take a good look at cable connecting the speakers since WiFi can be unpredictable depending on how many people are around. You might ask an installer for the Era 100 pro, that do Pwer Over Ethernet (POE).

First of all thanks a lot for your answer. This already clears the question stereo or mono So we will go for Mono then.
i already bought the Play:3 as the budget is small and i could get 7 piece play:3 + Sub2 for 750€ including all the wall mounts for the play:3’s, whereas the Era-100’s cost around 1500€ for 6 pieces (without Sub) in Switzerland. And 4 Fives are already around 2000€, what is to much at the moment as we are starting the store new and have a lot of investments to do. Also those are hard to find used (at least not at a decent price).

So we planned to use 6 of the play:3 and keep one as a “Fall-out spare”.

What is not really clear to me is following:
You say to do 5 Rooms with the Play:3 + 1 Room with Play:3 + Sub.
Why not 1 Room with 6 Play:3 + Sub? What is the advantage of putting them in 6 different rooms? Because it’s better synced?

Thanks a lot

Thanks a lot for your answer.
Unfortunately our budget does not allow this. 6 piece Era 100 pro would be 3000€ in Switzerland, and we got the 7 piece Play:3 + Sub + wall mounts for 750€.
Also the Era 100pro are not available in Switzerland (they say middle to end of february). as we are about to finish the store and plan to open in 6 weeks, we also don’t want to risk this.

A Sonos Sub can only bond to one Sonos Room.

A Sonos Room can be one Sonos, a Pair of Sonos or Home Theater set.

So you have two Sub options.

- Sub to one Play 3

- Sub to a stereo Pair of Play 3s.

Sync does not enter this issue, all will be in sync no matter the configuration you choose.

You might consider using the 7th Play 3 to Bond to the Sub instead of picking one of the six on the shop floor. Maybe put the 7th Play 3 in another space and the Sub in a corner of the shop for the most impact.

ok, thanks a lot for your answers, that helped a lot for the decision :)
we could put the 7th in the toilets (i know, if we bond tis one with the sub, there will be no lows in this speakers, but for the toilets should be enough i guess).
So far we did 7 rooms and grouped them, now we try positioning and trying if we even need the sub or not. It’s possible that we are even happy without the sub.

Thanks a lot for your help i think we will find a good solution now :)