Running subs on GCD via Rca

Hi, I have recently moved up a couple of rca y splitters to connect my Gain Cell DAC to my S300 and Dual SVS subs in stereo.
Now running XLRs for the pre and power connections and rca from the pre to the subs the gain needed to be brought up quite a bit to blend the subs to the speakers while falling a bit short.

Since the SB-2000 subs only have RCA inputs would you recommend a splitter from the xlr and reduce it to rca again or run a speaker to line level converter from the second pair of outputs on the power amp?

Edit, the subs gain knob still had some adjustments left in them. The next few clicks woke them up.

Leave it like it is as running the subs output level near the top of it’s range won’t hurt anything. Also you need to measure the output with a meter and not by ear or the subs will really be up to high.