I just received my s-10 subwoofer and I noticed that there are two RCA inputs (L,R) on the sub.  My receiver (Denon 3806) only has one RCA output for the subwoofer.  I currently have the RCA cable connected to one of the sub inputs.  I see that they sell Y adapters for subwoofer cables but I'm not sure if there would be any increase in performance if I were to use this adapter.  Could someone please educate me on the importance of this adapter.

Thanks