Newly added iTunes songs not syncing in Sonos import

I converted some DSD files (ripped from SACDs) to wav format in 16/44.1. I add the files in iTunes via "Add files to library" after manually copying the new album as a new folder under the given artist folder., under the iTunes root folder. The files play fine in iTunes, but when I sync the Sonos library, it simply doesn't import the files at all.
Advice appreciated!