I like to use 2 speakers with my MacPro. I am able to get one speaker to work. I use a dj software program to play music. I am not a dj - play music in my home for guests/self. I use a powered speaker Gemini, RCA cables - I love it altho the speakers have some feedback. I like to purchase another speaker, but before doing so, I like to know whats the best way to hook up the second speaker. I see djs with MacPro using an establishment's speakers - like to know if I took my Mac to a location how would I hook up the Mac to their speakers?