can hear a track in a mix on pc and headphones but not on phone!

this is mental, ive been given a backing track in mp3, and it cant be heard on a mobile phone but can with headphones or on a pc, when exported and played back with other tracks mixed with it, everything but the backing track can be heard on mobile phone speakers! . must be some phase thing going on, any ideas? ill ask the person sending me the mp3 to look at there export options but i need a work around for now. crazy.

Have you checked it in mono on the PC? If it nulls this way then it’s presumably a mostly mono track that’s phase reversed on one channel.
Or of course if it’s all very low frequency the phone speaker can’t reproduce it.

Upload a short snippet if you want…intrigued to check it out.

Try the Steinberg plugin Mix6to2 across the track to help narrow down the problem …

That has been my experience as well. Even worse than disappearing audio (at least that makes it obvious that some work needs to be done) is the stereo information that gets dropped just a little bit … something sounds off when listening, but not quite sure exactly what is off! Once you think of the stereo information possibly getting lost, it’s easy enough to go to where the problem is (though, not always that easy to fix it, at least for me …).