Cables for Bottom End of biamped RSIIb's

I am planning to biamp my Infinity RSIIb's with Class D on the bottom and tubes on top. I already have Zu Ibis cables for the top, but was thinking I could go to a much less expensive alternative for the bass cables. Anyone have a recommendation for low-cost cables with great bottom-end?

What about good old zip cord?

Or am I wrong in thinking the bass cables don't need to be high-end? Please fill me in on this.
I had the RS1B's for a number of years and was well served by Kimber 4TC cables on the bottom. At the price it would be easy to do a double run. The bass units of these speakers really get low and strong. I have good memories of my time with the Infinity(s).
They don't have to be expensive cables (how long will they be?) but good damping is a must. The D amp will provide good damping control, but high inductance cables (like zip cord) or really long cables, or both, will work against good control. Any good solid core or low-strand-count cable will be better than zip-cord, but the best inductance spec is NO inductance and that can best be achieved using separated runs (like Virtual Dynamics.) A cheap used pair of VD's will give you all the control the D amp can deliver. A double run is a good solution too as long as the cable you're doubling has low/no inductance as a single run.