So I was hoping you all might be able to help out a noob. This is my first real surround system. I own the Denon 3312 receiver and Klipsch RW-12D sub. How do I connect the sub to receiver? Looking for best possible option for best sound. What cord/cable do I need, as sub did not come with any?
Yes, this cable will work fine. FYI, just because it's more expensive, does not mean it will give you better performance. As long as you have shielded cable to protect from RFI, gold plate to protect against corrosion and it's the proper length, you're golden.
As to the need for a "Y" splitter, there should be no need unless wanting to boost the signal. Simply plugging into either the port marked LFE or if no LFE designator, either of the RCA in connectors will get you online.