WaveData.create(String filepath)
It is not a file-path, but a resource-path!
I tried absolute-paths and they all failed to load...
I tried relative-paths, and they also failed... (relative from "user.dir")
then I checked the source-code..
WaveData.class.getClassLoader().getResourceAsStream(filepath)
Which explained it... I'm now using WaveData.create(byte[] buf) as that just does what it says.
Please rename the parameter.