Smash Ultimate Tools
Smash Ultimate Tools
File Size Limit: 100mb Supported Formats: mp2, mp3, wav, ogg, flac, and anything else SoX supports by default. Warning: Compatible wavs is the sound file being converted to wav and resampled to 48000hz. Will add an option for resampling to any custom hz later.

Extra Stuff:

Convert any compatible format to nus3audio/idsp/lopus

Convert Song to Compatible wav

Convert vgmstream compatible formats to wav

Replace nus3audio sound banks with idsps