I've got some crackle and what I guess is electronic interference every now and then. How far should the power cords be from the speaker wires? I think my attempts to separate them have yielded some improvement. I'm not sure if any further will completely improve it so, I'm curious how can I tell if I have a receiver with bad soldiering or shorted speakers etc? What are the symptoms of these two things? I got my receiver from ShopOnkyo, it looks perfect on the outside and came with everything. This is the first time I've used these speakers (Polk Rtis) & this receiver so I can't isolate it to one or the other.