Subwoofer connection

Hello,

I just got a new sub that has XLR connectors for Right and Left.

My preamp has one pair of balanced XLR outputs and one pair of unbalanced RCA outputs. My poweramp has one set of balanced XLR inputs.

What's the BEST way to setup this sub?

I was thinking a pair of XLR Y-splitters to split the signal coming out of the pre XLR connectors sending two cables to the sub and two to the power amp; not using the rca outs of the preamp at all.

thanks for any info.

Thanks.