For subwoofer frequencies, I have found that a larger awg solid-core conductor works much better. The larger awg solid-core will transfer the bass energy much better and stronger than other conductors (smaller awg or stranded).
For plenum rated cable, the Beldon 1695A cable is very affordable and uses a very large 18awg solid-core conductor. Your Silver RXW-12 only has RCA inputs, so you don't need to worry about a balanced cable. Blue Jean Cables will sell this cable terminated with an gold-plated RCA plug, or you can terminate on your own with anything.
I generally think it's better not to terminate at a wall plate because you have one more connection and plug in the mix. Wall plate RCA jacks are more for convenience than anything else.
https://www.bluejeanscable.com/store/subwoofer/index.htm
A 25 foot terminated with RCA would be $78 from Blue Jean Cable.