XLR or RCA cable for Paradigm Seismic 12 sub?


I'm going to run a 15' cable from the pre/pro to the seismic 12 sub. I am just wondering if I should buy a XLR cable or a RCA cable? Would I be able to notice the difference?

Also, what are some good brands of XLR and RCA cable under $75?

Thanks.
jeweltone