I actually already have an adapter - I'd just need to purchase an XLR "Y" splitter cable.

My SVS's are going to a Behringer DEQ2496 with RCA ended sub cables and an RCA to XLR plug. Then I run the two cables from the DEQ2496 with small "patch" XLR to RCA cables to a good quality "Y" splitter which connects them to my current sub output on the Ref 31.

So I guess that I could reduce the number of cables by going to the unbalanced dual inputs and cutting out the RCA y-splitter that I have, but if there is some benefit to using the balanced sub output, all I'd need is that XLR Y-splitter and I could cut out the XLR to RCA cables from the Behringer to the 990.

So am I going to get a better signal by using the unbalanced RCA sub outs or by Y-splitting the balanced XLR sub out?