@Nzo: Check this out, I've added some sound fx functions.
Not really playing samples from xm file, as I've noticed that in some musics those samples are almost useless because note/pitch.
Instead I've made it play any ".wav" file simultaneously, you can load from memory or open a file.
There's an example included to show how to load from memory or file, press F1 or F2 to play samples while playing a music.
Enjoy

{Edited - tinyptc_ext++ now have sound fx replayer}