I have a pioneer vsx-504s reciever that has a line level sub pre-out, however, my sub(one I stole from a cheap souround sound in a box)(temporary solution till I get my tax return)is speaker level. I have chopped a white from a pair of RCA's, stripped the jacket, beaned my outside copper(im assuming it's neg, but as long as I keep it the same on the other end, it's fine)to the black of my 16G speaker wire, beaned the shielded inside conductor to the red of my speaker wire, and I still haven't heard my sub. What am I doing wrong?