What’s the reason I can only upload in FLAC and mp3, not WAV?

Hi DJ_PY,

Thank you for your question, it is one that I had for awhile when I first joined.

To be clear, you can upload in WAV if you absolutely must, by putting the file in a zip archive.
The preference for FLAC is the quality retained from decompression.
Lossless also means no artifacts from mp3 encoding, which means 100% sync of stems.
WAVs are essentially CD quality files with headers, but no compression.
This means more bandwidth and storage on the host’s end, and longer download times for other members.
(Please also note that there is a 50 meg limit for uploads).

I hope this has answered your question; please let me know if I missed something.

Kind regards,
Apoxode