I have an audio file in various formats which play just fine independently using the HTML5 <Audio> tag and <EMBED> and <OBJECT> and <video> etc tags...
I have added and tested the "loop" parameter which works fine.
I have added and tested the "controls" parameter which works fine.
I have added and tested the "autoplay" parameter which works fine.... only on FM PRO. It will not work in FM GO.
(sorry did that from memory so it is probably wrong but I hope you get the picture)
I have mp3 and wav files... and they are tiny.... and all will play on the iPad with the controller. Interestingly on my iPad mini I can't get the sound at all.... but I can on an iPad with Go v 12.
I am pretty sure it is iOS 7.1.2.