BIWIRE TERMINALS

I recently purchased some JPS Lab speaker cables (single wire). I was shocked at the difference better cables made over the ANCIENT Monster cable I had been using. Now I've upgaded speakers (sort of fell into something and did it) and they can support bi-wiring. It sounds like bi-wiring is the preferred way to go. BUT can someone tell me if anyone manufactures an adaptor that would allow my single-wire positive and negative leads (spade terminations) to be converted to a "bi-wire" termination. I can imagine how to do it crudely with a visit to the hardware store but wonder if there's a product designed for this purpose. Thanks in advance.