The Quick Answer:
We recommend high quality M4A or MP3 files.
Songbox sets itself apart from other audio streaming platforms by allowing you to upload any file type you like, and then not compressing it for your listeners.
This is a great feature for sure but there are some things to consider
The Streaming Experience
Apple and Android devices don't like WAVE files
In order to start playing a WAVE file, the entire file must be downloaded. Also, if the file isn't downloaded within a reasonable time (a handful of seconds) then it won't play at all.
This is a limitation of iOS and Android and there's nothing that can be done about it.
MP3, M4A and similar formats are preferred for streaming
These file types can start to play when the track is still only partially downloaded.
But what about audio quality??
Yes, we here you! But here are some things to consider:
Almost no-one listens back to audio on a system that takes advantage of the extra sound quality in a file format like WAVE or FLAC
Listening happens on phones, bluetooth buds, laptop speakers, on public transport etc etc
A quick, frictionless playback experience is massively more important than trying to eek out a little bit of extra audio fidelity that most people won't notice anyway. High quality MP3 and M4A tracks sound great!