I read a thread in www.blu-ray.com a few days ago about dual subwoofer hookup for home theaters. I had an extra 8" Sony subwoofer laying in the closet so I decided to hook it up with the 8" Sony that's already being used. Drove to BestBuy and purchased a Y-splitter cable and a subwoofer cable.

I inserted the male end of the Y-splitter to the reciever, connected my 8" woofer on the left of the tv to the white female connector of the Y-splitter, and connected the extra 8" woofer laying to the right of the tv into the red connector of the Y-splitter (colors don't matter, but good for reference). I tried out a movie, and what a difference it made! Two 8" woofers hitting at the same time makes louder and stronger thumps! Since I now have a woofer on both sides of the tv, bass sounds more centered, evenly distributed. Absolutely awesome, you gotta try it, an inexpensive home theater upgrade.