RCA to XLR cables

I know they make cables for this but is the signal balanced at the xlr input? I've been told it's not. Is that a big deal?

What is a good source for those cables? Is Monoprice ok or does it pay to buy more expensive ones?

This would be going from the variable RCA outputs on a Rogue Cronus Magnum to the XLR internal amp input on the speaker which would be set to bi-amped mode. Speaker terminals would power the mids and highs.