These files are for XENOPixe/XRGB cores.
When I purchased my core, I did not get an SD card so I searched arond and found these files.
V2 has 34 soundfonts.
V3 has 35 soundfonts.

There are v2 files and v3 files for XENO RGB and XENOPixel cores.

They may be from DarkWolf and/or some other vendor(s).
They all work fine.
The v2 soundfonts have font.wav and track.wav files that use audio from Star Wars that the v3 files no longer contain due to copyright issues. 
You can use the v2 files in v3 cores and vice versa. 

I used the font.wav's and track.wav files from v2 and copied them to where I wanted in my v3 setup.

I included the latest update.bin files that will upgrade the firmware if you want. 
You can copy the update.bin file from the appropriate version (2 or 3) into either the 'set'' folder (v2) or 'setting (v3) folder to update the core.
Or you can contact your vendor and get the firmware update and possible the entire 'set' or 'setting' folder for the update (preferred if you can get their support.

I could not get a reply or support, so I searched around and these were the files are the end result where I got the updates for my cores and the default soundfonts for the cores.

MTFBWY