Hi Pgrillone, For the life of me I can't seem to get my system hooked up and running. I am using a similar set up as you (Bose L1, Behringer X1222USB mixer, wireless mics and laptop.) I have my laptop connected to the mixer with USB, Laptop connected to my tv through HDMI, wireless mics are in the 1 and 2 input XLR. I'm using the stereo rca out on the mixer to the stereo rca input on the Bose L1. The microphones are working fine to the speaker, but for the life of me I can't get any sound from my source (laptop or iphone.) In your diagram, it looks like you are running XLR to 1/4 inch. Is there a benefit to hooking it up that way over using RCA out? To get sound to the mixer, do I need to change some setting on my laptop? It looks like the mixer is showing music playing (via the led inputs) but just no sound. Please help if you can think of what I'm not doing right. Also, do you get sound at the tv monitor and speaker? If so, do you normally mute your monitor for karaoke use or leave sound on?