Sounds like you’d be better off with a mixer. Like this (the one I have and love):
http://www.sweetwater.com/store/detail/ZED14?utm_source=Google&utm_medium=PPC&utm_campaign=none&device=c&network=g&matchtype=&gclid=CL_629zLhboCFSRxQgodt1UA2g
Probably most trying thing you could with your set up is to try to do it without a mixer.