Audio [Q] adress music to BT connection instead of wired headphones

Ciao all, i've some conflict in using BT headphone and having heartrate belt receiver connected to the headphone jack.
I mean, if i connect the receiver to the jack my Note2 switch automatically music from BT connection to the wired one, so if i use heatrate belt i cannnot hear music!
Heartrate receiver is a pass-by one, it has a jack that goes connected to the jack in the phone on one side and from the other side has a jack-in hole that allow to connect a wired headphone.
Can anyone suggest how to change default option to make BT connection the default one for headphones?