I am very new to the world of DJ'ing. I just purchased an Ion Discover DJ controller and an external sound card. I've been messing around with it using Mixxx and can't figure out how to get sound to come out of my stereo and my headphones for cueing. There are 3 options for output settings in Mixxx preferences: "Primary Sound Driver," "Realtek High Definition Audio" and "USB PnP Sound Device." I think the last one is the sound card that I bought. I have tried all combinations for Master and Headphone output and I cannot figure out how to get sound to go through both... I'm sure there is a really simple answer to this but I have tried using the Mixxx manual and searching the forums to answer it myself and I couldn't figure it out. Thank you in advance.