Although we value the aesthetics of imperfection in music, we expect your WAV file to be digitaly perfect. There should not be any digital imperfections such as hiss, impulse noise, crackle, wow and flutter, background noise, skipping / timing errors and such. Our advice: make sure to listen carefully to your exported WAV file, start to end, before you upload it.
Minimum: 16 bit, 44.1 Khz, stereo.
Recommended: 24 bits, 48Khz or 24 bits 96Khz.