It is not possible at the moment, I tried looking for a solution the moment I got it early june but the only solution is the 3rd party app doubletwist for playlists.
5.1ch is not supported.
So, the only way to use 5.1ch is with default player, right? My "problem" is i organize the musics by folders (not by tags) and at the begining i searched another player with playing by folders, but with no 5.1ch, isn't the same. So, to keep using 5.1ch i need use the default one but i can't put playlists appearing on the player, i already search how to do it, but i'm still can't. Create playlists on the phone, is painfull. Using default explorer (or astro) and go to the music folder and open a music, it opens and play the files on that folder, but the problem is it opens on sound player and not on music player (so, no 5.1ch on sound players). After all, i still can't do what i want and i guess it's a simple thing.
Hope you understand what i wanted to say and sorry for my bad english.