Double storage of the same audio files
Using Jamroom
The original uploaded version could be a .wav or any of these file types:
aac
aif
flac
m4a
mp3
ogg
wav
wma
The only file type that will play on the web is .mp3 so an .mp3 file is created to be played on the web. There are options to just play a sample of the mp3 then only deliver the original to the purchaser of the song.
In your case it looks like the original is the same as the conversion so its not really needed in your case, but in cases like if the original was of a very high bit rate a lower version would be played on the web.
In short,
* The original is stored to reconvert off if anything goes wrong.
* The original is delivered if the item is sold or downloaded.
* The other version is a playable net version.