Hi there.

If you have Bose (and I suppose other other makes of Wi-Fi speakers) the documentation is not clear on how to play FLAC --Wifi is streets ahead of Bluetooth for decent sound quality - also you don't need to bother pairing devices - and of course while paired you are using usually a mobile phone for playing music.

Accessing FLAC from your NAS library DIRECTLY gives problem --Content cannot be played on this device -- however it works by using PLEX.

So install PLEX (free) and add music library to PLEX. Note if you have large music library this will take a long time initially but after that updates go quickly (adding / removing music). Of course it's just a LINK to your library -- it doesn't physically store your NAS music on your phone !!!!!!.

So after installing PLEX and adding your music Library to it :

1) install the Bose Soundtouch app (free) on preferably your mobile although available on Windows and Ios.
2) set up your wifi speaker(s) - usually quite simple --follow on screen instructions.
3) in the BOSE app add music library -- you should see your PLEX server -- add that
4) now you can browse music - by folder / album etc etc etc and it will play (FLAC included) -- a really nice get around.

Note on the Bose speakers you can also adjust the Bass by using the phone app -- go to settings and click on the speaker you want to adjust the Bass on.

If you have these high quality Bose speakers - don't hobble the sound by using Bluetooth --Wifi is STREETS ahead and once you are playing the music you can turn the phone off (if you use the phone app) These speakers also play directly Internet Radio from Wifi too - 6 presets available and with a handset too.

Both PLEX and the BOSE app work fine on W10 --bye bye Bluetooth !!!.

Also good if you have several of these speakers - each one works indivually too and using Wifi you don't even need a computer or your phone to be on.