Subwoofer interconnect quality question

I have a pair of GoldenEar SSX's in my 2.1 system and currently use DH Labs Air Matrix RCA's from PS Audio BHK preamp. I Synergistic Research interconnects in the rest of my system.

I've heard that higher end interconnects are less important to LF transmission in subs.

I originally had Synergistic Research Element Copper RCA's on the subs but switched to DH Labs when I moved sub 10' from preamp for better placement since don't have longer Syn Research cables .

That said, I recall better separation, weight and bass clarity with the Syn Research Element cables over DH Labs.

Confirmation bias, or do subs respond well to higher end RCA's?