Recently I brought a Sunfire Powered sub home to demo and to maybe replace my old sw10. I have a Denon 3801, and I am running FR-3 IIs, a RC3 II, and RB-3s. My speakers are all set to large through the denon setup and I have it set to LFE mode. I am also powering the Mains with a NAD 218 amp. When I hooked up the sunfire I ended up getting a really bad hum and some distortion out of my main speakers with the volume all the way off. I have never had this type of problem before and when I took the Sunfire amp back to the store, they hooked it up to one of their systems and it sounded perfect. The store then gave me a Mirage amp to demo at home and that sounded OK and was hooked up the same way the Sunfire was as well as the sw10. I am using the line input with a splitter.
Has anyone heard or know why this is happening with the sunfire amp, is my configuration supposed to be a different way? Any help would be greatly appreciated.