Bi-amp cables for woofers

Does anyone have any opinions (i know, dumb question) on the best cable for the woofers (my case PBN Montana EPS2)in bi-amp config. I've got plenty of bass, but not as tight and fast as my mids and highs w/Trans. Audio Ultra MM2. My amp has great control-Spectron Premiere 7.
Thanks,
lubes3