I have a JVC KD-AHD59 HU, front components and a Polk 4ohm SVC sub. I am planning to run the front components on ch 1/2 and bridge the sub on ch 3/4. The HU has 4 preamp outputs, line out L/R for the fronts and L/R outputs for the sub. I'm confused by the L/R sub outputs. Can I run those 2 sub outputs into ch 3/4 inputs on the amp and bridge the amp outputs for the sub? Seems odd to me. Please advise. Kent