D888 - loading stems created in DAW, missing .SND file

[aaahhlol]

I've read the manual and understand filename and wav requirements for loading songs on to the D888.

Files should be TRK01VT1.wav, TRK02VT1.wav, ect

WAV files should be PCM, 16-bit, 44.1k

When I copy a set of files to the D888 USB folder, I finish the transfer by pressing USB on the D888.

The folder is there, but is not viewable in the list of songs. I do not have a .SND file in my newly created folder, where the existing demo folders have a .SND file.

How do I get the D888 to create a .SND file? It is binary and not something I can manually create myself apparently.