Need help with a hooking up a sub.

Hi All,

I've already done a search, but I can't find the answer to my problem. I want to integrate a 2 channel system to my HT setup. My rooms has 3 subs that have been optimized with a Behringer external crossover/equalizer. The DAC/preamp that I'm looking at getting has 2 balanced and 2 RCA outputs, both putting out signal simultaneously.
I plan to run the balanced channels out to a switcher. The question is how to hook up the 2-channel to the Behringer, which only has balanced inputs.
I've read opinions all the way around. One channel RCA to XLR connector? 2 channel RCA to one XLR? Both channels RCA to XLR and let the Behringer sum the channels up? I prefer not to do that, since then I'd have to switch inputs all the time on the Behringer.
First word problems, I know.

Thanks,
David