Hopefully, I'm posting in the right area. I purchased 2 Sound Storm Laboratories LOPRO10 10 Inch Powered Subwoofers. Both with 2 RCA inputs L & R . No outputs. I have 1 RCA with 2 cables labeled L & R. I have the RCA plugged in the L channel on 1 sub and the R channel on the 2nd sub. My problem...