Where’s the picture???

my two cents: take the opportunity to foresee ethernet wiring at any potential (future) speaker point with power sockets (since Sonos does not support Power-Over-Ethernet) - TruePlay will help to ‘align’ the sound diffusion of the speaker positions

Hi

Let me be honest….the design of your space with the current seating/dinning arrangement does not effectively lend itself to surround. Placing surround speakers overheard or using Sonos One SL’s on stands (in any position) will not yield the benefits of speakers properly placed. Using TruePlay via the Sonos App (which requires an iOS device) will not correct the surround effect for improperly placed speakers in your space with the current furniture arrangement as shown in your picture. You would have to rotate the objects (seating/dining) 90 degrees placing the dining behind the seating area for proper surround enjoyment.

An optimized surround setup should appear as in the picture below. In-ceiling speakers ( with the recommended furniture changes) even installed at an angle over the seating area would be effective with TruePlay tuning (adding the sub is optional):

If the design; or more importantly the furniture arrangement, shown in your picture is not the intended final setup please submit a corrected photo. As your current design appears ...just adding the Beam would be the only Sonos product I’d recommend for TV. FYI, the more expensive Sonos Arc would yield better effects as a speaker even without surrounds.

If you stay with your current design/layout You can still add in-ceilng speakers for music powered by a Sonos Amp. Doing so will allow you to stream via your favorite on-line source or play tunes via AirPlay2 that are resident on your device. Streaming and Airplay2 to a Beam or Arc is also possible. In fact the Arc or Beam could be paired with the in-ceiling speakers to enhanced music enjoyment.

Feel free to comment and ask more questions.

Note: Some may have a different opinion than I.

Thanks for the suggestions. El Rubio, yes we are planning on additional Ethernet points.
AjTrek1, we have an Arc, surrounds and sub in our main living room and perhaps I’m being a bit greedy trying to do the same in the dining room. We could rotate the sofa to face the TV but then it gets in the way a bit. Probably it will be best to abandon the idea of tv surround sound and just concentrate on half-decent music. 
That being said, I’m still a bit unsure about relying on speakers mounted in a sloping ceiling, how many to have and how to configure them. I guess the main listening positions will be standing in the kitchen (facing the windows) or sitting at the dining table. 

The obvious alternatives are either a load of ones or maybe the new Ikea Symfonisk picture frame speakers (or combination thereof). 
Any further thoughts gratefully accepted!

Hi

Can you upload a floor plan layout of the room that shows where the openings are for doors, windows, skylight as well as cabinets and counter space? It’s difficult to make recommendations for speaker placement based upon the view you have presented.

hi @NickWr I have the best experience with the Sonos One SL, not only for the price/quality but also because of its size and mounting options - many of my Sonos Ones are wall mounted with the Vogel products. I have no experience with IKEA’s picture frame speakers but use the Symfonisk shelf speakers which I would only recommend to use in small rooms. I have several times changed the position or added speakers to improve the sound in some rooms. This is something you may want to foresee as well. 

Thanks both. We have a couple of the symfonisk lamps, which seem similar to Ones. Haven’t heard the shelves or picture frames. 

I’ll post a floor plan which shows the overall dimensions. The black bordered rectangles are kitchen cabinets & island. All other furniture will be flexible. 
 

hi @NickWr thanks for sharing the floor map - in my humble opinion this will mainly help to define potential speaker mounting points - with regards to the placement of sound sources, I would take as reference who and when listens to music or TV broadcasts - as an example: does anybody listens to the news or music during cooking or washing dishes? if the answer is yes, you should foresee a speaker (e.g. One SL) at these locations

@NickWr

Thanks for the floor plan.

From what I can surmise the facia above the folding glass doors runs the length of 6000mm. Four (4) Sonos In-wall speakers by Sonance could be evenly spaced across to provide adequate room saturation for music. The arrangement also lends itself as the perfect solution for background music during dinner to allow it to flow overhead versus coming from a pinpoint direction.

A Sonos Amp could be placed inside a cabinet with electrical and Ethernet ports to create the SonosNet or strength it if already established via other Sonos. The Sonos In-wall speakers by Sonance could also be tuned to the room via TruePlay with an iOS device.

Doing so would provide a clean professional look versus Symfonisk Picture Frame speakers with electricals hanging down. I’d even prefer in-wall speakers versus Sonos One SL’s mounted on walls or placing them on counter tops. That includes Sonos Moves and/or Roams. The only reason for the latter would be for portability and/or Bluetooth connectivity.

A Beam or Arc could still be incorporated with a wall mount below the TV on the far wall as you originally intended. Activating the Alexa or Google assistant could also command the in-wall speakers. 

The Beam/Arc could be grouped to the in-wall speakers to enhance music for entertainment. I would not recommend grouping for TV broadcast as there is a 70ms delay that would create an echo effect.

I’d be interested to read your thoughts on this proposal assuming that it is structurally viable.

Note: With a 2nd Sonos Amp and two (2) additional Sonos In-wall speakers by Sonance you might install one on either side of the wall mounted TV. The speakers would only provide a “phantom” center channel vs a dedicated center with a Beam or Arc. You’d be advised to space them at least 304mm to either side of the TV to accommodate a larger screen if desired in the future. Also a Sonos Sub can be added to either Sonos Amp to enhance the low end. However, each Amp requires it’s own dedicated sub.

@AjTrek1 thank you for the very detailed response.  That sounds like the best way forward. I am unsure whether there would be sufficient room in a fascia above the bifolds but if not it will certainly be possible to fit ceiling speakers just above the bifolds. 
it will be a few months before we are at that stage, but something to look forward to in the new year. 

Hi @NickWr 

Glad you think my suggestion may be doable (i.e. in the facia above the bi-folds or in-ceiling in the relatively same position). Here’s another suggestion to consider…

The Sonos Amp can power six (6) Sonos In-wall or In-ceiling speakers by Sonance (only).  That said you could stratigically position two (2) more speakers in the space. Said installation could be done at time of construction or pre-wired for installation at a later date for budgetary considerations.  

Pre-wiring for In-wall speakers for the TV could be done as well.  You could use a Beam or Arc mounted on a cabinet (below the TV) in the beginning to prevent marring the wall; if you’d like to consider in-wall speakers at later date.

Also, if using the Sonos Amps inside a cabinet (that is part of the construction) remember to run Ethernet and electrical inside (as I mentioned in my previous response). I would also run Ethernet and electrical behind the TV for a clean look. Ethernet for the TV will be handy for updates and smart TV apps like AppleTV, Netflix etc.

Just a few thoughts 

Note: Speaking of two additional speakers it appears they could be installed in the facia that runs the length of the wall across from the bi-folds and over the door way. IMO one would be placed centered in the area that overlooks the sofa in your 3D rendering and the other behind the sink area.

Thanks @AjTrek1 - all good points. 
I am still undecided how to configure the ceiling speakers in terms of channels; I.e. would it be better to have four speakers above the bifolds in two sets of stereo pairs (so running along the window they would go LRLR) or one big stereo zone (LLRR)? I suspect the latter. 
if we also went for another pair on the other side of the room as you suggest, it’d probably have to go:

L L  R R

  L     R

The cost of that setup is starting to get fairly uncomfortable if using the Sonance speakers, but I see that is the only option if you want trueplay and/or 3 pairs powered by 1 amp. 

Hi

Actually, when using multiple pairs of speakers in a space as yours traditional logic is to set the Sonos Amp in mono. In that setting no matter the position of the listener the sound is the same with no loss of content. For example the listener doesn’t hear an instrument  that sounds miles away.

Stereo is best enjoyed with only two speakers forward of the listener. In your space the goal is more about coverage than stereo separation.

You might consider volume controls for each pair of speakers to better control the level in certain areas or turn a particular area off by lowering the volume. 

As I mentioned previously you can pre-wire to add the two (2) additional speakers later for budgeting considerations. You could mark the locations with a wall picture.

Note: The additional 2 speakers could also be wired to another room as long as playing the same source in that area is not prohibited.

Note: Yours is an aggressive project if you decide to take the route I’ve outlined or a variation. I would highly recommend consulting a professional installer. Not just to get it right but also for warranty of the installation. Dollars spent today with a professional may well be worth it later on.

@NickWr

Hi

I hope you get an opportunity to read this and my previous post above. I have one more option that you might consider that negates running speaker wire for in-wall or in-ceiling installation as well as measuring for openings in the wall and may provide better control.

I’ll use US measurements in this explanation. Installation of the proposed speakers would be mapped prior to installation of the finish wall surface.

During construction of the under-wall consider running a 1x6 board at the top of each wall and a 1x4 board at the bottom and 1x4’s spaced every 18 inches in between. Doing so provides a nail surface for the finish wall.

Now let’s consider wall mounting Sonos One SL’s in the position where the in-wall speakers would have been. The installation of the 1x6 allows placement of the One SL’s (with appropriate electrical along side it) without having to worry about locating a wall stud for installation of the speaker wall mount. A short power cable would be used as shown here. I’m sure the same can be found in the UK.

Note: One of the speakers should be a Sonos One with voice assistance capability.

Each speaker would be named accordingly such as Kit 1, Kit 2, Kit 3 and so on. Those speakers could be set as stereo pairs according to your design. The stereo pairs could be broken at any time depending upon your need. Volume would be controlled by your device either individually or as a group. 

I hope this helps as well.

Thanks @AjTrek1, food for thought. I have a month or so to ponder it before the build gets to the appropriate stage. 
Your advice is much appreciated, thanks for taking the time.