You can mount the Boost either way. The orientation won’t change the way the Boost works.

thanks  for  the reply    TV Aerials have either horizontal or vertical polarisation to prevent adjacent transmitter  interference.  I assumed that whatever radio waves the Boost uses would have a similar effect and as the boost is not a cube I assumed it would work best aligned in one plane which gives the best aerial length and connection.  What am I missing? BillMR.  

FYI… the Move only uses Wi-Fi or Bluetooth. The Boost creates a SonosNet mesh network that the Move will not connect to.

Perhaps these photos of the Boost’s internals will help answer your question: https://fccid.io/SBVRM008/Internal-Photos/Internal-Photos-2376016

You could easily Google ‘Sonos BOOST wall mount’ and see lots of options from various manufacturers. I would assume that if one orientation was the only ‘correct’ one, there wouldn’t be all of the various options. 

Compulsive types can actually check out how the different positions work by invoking the Matrix for every position; the Boost performance numbers will tell the story.

I have not had reason to place it other than on a flat surface, but I suspect positions don’t affect performance as long as all maintain the same line of sight - or absence of it - to the target Sonos speaker, and the distance from it.

Typically, the radiation pattern of this sort of device is somewhat hemispheric. You can experiment with orientations. If the device covers the area of interest, then that orientation is successful. Mapping the radiation pattern requires a specialized laboratory.

I have not seen a radiation map for BOOST, but I would expect that in most situations horizontal would be best, however if I was attempting to cover an outside area, vertical would be interesting.

While I don’t think that this matters for BOOST, sometimes the inverted position interferes with cooling. I have a network switch that will overheat if I mount it inverted.

However, BOOST will not extend your MOVE’s range. See this article.

OK. Thanks to all of you.  It never dawned on me that the Move which we only use in good weather does not work with Sonos net.  I get limited WiFi in the garden and I just assumed a Boost to extend the Sonusnet would solve the patchy Move reception and dropouts.  I have obviously wasted my money buying a Boost as my Sonos system in the house works fine.  Why have Sonos made a product that doesn't connect to their own Sonos net? I obviously would have better spent my money on a WiFi extender. So much for using my bad weather Lockdown time to cure perceived summer problems.  Thanks again.  BillMR