You have the option of integrating your NAS into the Teufel Streaming System via your network. This way, you can set up a library with the music stored on the NAS and play it via the Teufel Streaming App.
To do this, go to the settings in the Teufel Streaming App, then to the menu item "My Music Library" and then to "Add resource...". Here you can include your network drive (prerequisite: the drive must be cleared to use within the network).
Menu "My Music" > Add resource and enter resource.
After that, you can use the app to play your music stored on the NAS via the streaming speakers.