FLAC files in your music library can have a maximum bit depth of 24-bits and a max sample rate of 48kHz. If you are running the S1 app, the max bit depth is 16-bits.

If it is a WMA file, the max bitrate is 320kbps.

https://support.sonos.com/en-us/article/supported-audio-formats-for-sonos-music-library

24 * 48 kHz = 1152 kbps.  I believe my flac files are under that limit.  Anyway isn’t this just a limitation of the codec SONOS is using.  I have open source (free) software that will play these files and a $100 Audiocast device will play them fine. 

Is that wirelessly to 32 speakers around the Home? I doubt any human from the planet ‘Earth’ would hear any difference between 24-bit/48kHz audio and the same tracks set at a higher resolution anyway, particularly on speakers setup in a Home environment.

Currently just two passive speakers connected to the SONOS amp (wires) and currently the PC and SONOS are both on the wireless network.  I am planning switching both to wired connection to my router to improve reliability.

I think that my flac files are not that exotic.  They are just a standard rip of CDs using the Windows Media Player application.  I would like to avoid re-ripping all of the CDs as that would take a fair bit of time.

I have confirmed my files are not exceeding the 24 bit/48kHz SONOS limits.  They are 16 bits/44.1kHz. 

In that case, they should play fine on Sonos. Are you playing the tracks via a shared library added to the Sonos App (and indexed) to your Sonos devices?

Only I see you mentioned some kind of server in your opening post… maybe see these Sonos Links:

https://support.sonos.com/en-us/article/add-your-music-library-to-sonos

https://support.sonos.com/en-us/article/supported-audio-formats-for-sonos-music-library

Sometimes Sonos can get fussy about file names. Copy a couple of your trouble files over to ones named x and y, reindex the music library and see if the renamed copies play.

If you are using some method other than the music library this may not apply.

Success! 

I was using the Windows Media Streaming options.  This did NOT work with the flac files. Kind of confusing as the WMA and MP4 files worked fine using this approach and I have used this approach with the Audiocast device without problems.

What worked was sharing the Windows Music folder and bringing it into Sonos as a Music Library, as per Ken’s suggestion.  Thanks Ken.

FYI I created a local account for the Sonos to use to access the folder just so that I did not have to give Sonos full access to my Windows machine.

Also how to examine audio files without installing software onto your machine: Metadata2Go

On to the next part of this project: cutting holes into the ceiling of our recently renovated house.  My wife can hardly wait. 

Thanks everyone. 

The answer to this is usually flowers, wine and chocolates.

If you get tired of using your PC as a file host you can easily switch to a NAS device as the Music Library host.

These days it isn’t a bad idea to have a NAS for backups anyway.