Ok so i normally do my mixdowns to mp3 format simply because its a smaller file. I have a lot of friends on facebook so i send them my finished songs or works in progress to get input. Wavs sound better but they are too big too send in messenger. Anyway i keep having an issue where some people i send the file to cannot pkay it while others can. I dont understand thst. Not sure if its a mac/iphone pc/ios thing or what. But its very annoying. Any suggestions? Thanks