Another question about bi wiring

I used two sets of kimber kable 8tc wires.one for uppers one for lowers on a set of nht 2.5i.i connected them at the amp using banana plugs that have a screw in lock on them plug one in the amp the other in the banana plug with the screw hole to lock in the other plug.i think it sounds better.does any one make a 2female to male banana plug.thought about using a spade connector  also .if you use wire jumpers what is the difference with that or the bidding straps?cheers Bob