CDJ-400 / Reckordbox compatability

Well im using windows 7 and have 2 cdjs 400 i hooked everything both usbs to computer turn on the rekordbox and everything works good the only problems is the audio its only coming from one cdj. It's like left cdj i control left rekordbox deck and right cdj i control right rekordbox deck but the audio from right deck is coming from deck on left can you guys help me?