I can always hear the radio (station uncontrollable) on my center channel. I have an Onkyo TX-SV595 and no matter what input is selected or how the volume is adjusted or what radio station is selected, there is always a faint radio station coming through, on only the center channel. I tried the powered and preout outputs and they both do it. Should I try to have it fixed, or do I need a filter somewhere? Thanks.