The purpose for FLAC is not an audible difference, it is because it is archival. WAV is how the album is originally distributed, that is how it should be archived. FLAC is just a container for the WAVE data. It is very much like a zip or rar, only it is playable and has better compression. You want to have the original product in your archive, that way you are always working from an original non-tampered source. You can't hear the difference between modern lossy codecs and FLAC. You just can't. If you say you can, you are either lying or have been deceived through the placebo effect. BUT, a lossy codec always throws data away. Data you can't get back. If you decide down the road to make a different lossy version because better ones come out, you are working with incomplete data if your archive is MP3. Your result is always going to be worse than if you had the original wave data to work with.
The difference between WAV and FLAC is absolutely zero. You can compress and decompress a wav file thousands of times with FLAC, and the final WAV you get in the end will pass a 128-bit md5 checksum made of the original.
I always throw this link at people who think they need WAV instead of FLAC.
http://flacfox.blogspot.ca/
