WavPack is in charge of WAV audio file compression/decompression, its main characteristics is that it does not loose quality compared to the original one.
Compression in other formats such as mp3, reduces quality to decrease the file size, but his does not happen with WAV ones processed with WavPack.
In this way you may reduce the size of your music in WAV till a 50 per cent and you will keep its quality and retrieve the disk space.