I connected my XM Roady to the AUX port and it sounded terrible. The XM Roady has a line level output but this output can be adjusted. I adjusted it all the way up and it sounded better than the FM radio but still not as good as the CD player. I think I saw a cable that will let me connect a line level output to the SAT input (sort of like a PIE/Blitzsafe cable). I'm going to try it out.