How to mount Sonos 100 in a kitchen with a cluttered wall underneath the speakers.

That wall is quite a challenge! I don’t see much other than your own suggestion. There’s no upfiring speaker on the 100’s so I don’t think there’s any need to invert them, and they could go close to the ceiling if necessary. If the sliding door slides into a pocket, be careful not to obstruct it when mounting the speaker mount! 
 

Alternatively, can they go in the kitchen space itself: under wall cupboards, for example? They are useable as bookshelf speakers, needing only a very small clearance space around them. 

We put our Sonos on top of the kitchen cabinets, sound is good and they are out of the way. With most cabinets it is easy to run power from an outlet below them up through a gap in the cabinets and to the speakers. 

If it has to be that wall I'd put them in the corners and run the wires up to them in a paintable wire channel in the corner.

Thank you both!

For some reason, I had it stuck in my head that they had an up-firing channel. Good call on the slider clearance. I can just see driving a molly screw through the door and wondering why it wouldn’t close…

​@Stanley_4 I thought they are supposed to be at least a foot from the side walls. Am I confusing with the 300s again?

Right now, they’re on two opposite sides, kind of firing at a diagonal towards the counter. If course, the angles immediately go out of balance because the speakers get moved a bit or rotated. I want them on that wall so they face the stove, countertop and kitchen table (when clear). 

I agree black cords wouldn’t look great running down the walls. Thank goodness for paintable cord covers. I can leave the neutral beige or try to match something to the wall paper. My good night vision makes for lousy color vision. I’ll need someone in the house with good color sense to decide  what color is best for the cord covers.

Thanks again. I have the speakers connected to the mounts but stopped all work on the mounting plates until I understood better.

Let there be music!

The 100 owner's manual has good pictures of the driver locations, no real placement restrictions like the 300s have. They do work the same as conventional speakers where corner placement enhances the low frequencies, not a bad thing for small speakers.

I have one of my One speakers that is wall mounted inverted so I can use the touch surface.