In the configuration of PlayJoom must to be set up the folder in which you have your audio files. In this example can you see in the option Path to files folder the path c:\audio. And configure the maximum file size, which is allowed to upload. For example 400MB. At the end you have to Save & Close the configuration of PlayJoom.
Note: Do not configure a flash at the end of the file value, like: c:\audio\myfiles\