PSW450 connection help (Sony STR-DB830)

I have just purchased a PSW450, and I was puzzled by the 4 wiring options in the documentation. I am not an audiophile, but do appreciate good sound. What is the best option for wiring the PSW450 to my STR-DB830 Sony receiver? It would seem from both the Sony and Polk documentation that the pre-out option is best, but I don't understand why there is a left and right for a sub-woofer. The Sony doc says the pre-out signal is the same from left and right, and the suggested "Monster" cable that Circuit City recommended (at a hefty price) is a single RCA plug. Does the PSW450 need input to both RCA jacks with a "Y"? The Polk doc seems unclear on this. Do I need a "Y" out from the pre-out too? The Sony doc shows a single cable to the sub-woofer.