IME, IF a speaker is designed to be bi-wired, it invariably sounds better without jumpers. A true bi-wire cable works best. While I tend to agree that a single cable split at the speaker end to a bi-wire connection is probably not the best solution, two separate cables is. ( although I prefer a bi-wired single cable vs. stock metal jumpers that are usually supplied by the manufacturer of the speaker).
Free Tip for Jumpers
If you have already replaced the stock jumpers on your bi wire speakers I found this to be a nice boost in sound quality. It was a Nordost section of Music Direct, FYI.
Enjoy!
Diagonal Bi-Wire
For those looking for maximum performance from their bi-wire speakers, Nordost has a recommendation. Connect your speaker wire to the speaker as follows: Red lead to the Red midrange/bass post, Black lead to the Black tweeter post. Then insert the Norse Jumpers as you normally would, sit back and hold on to your socks. The effect is astounding, with greater focus, detail and less haze and grain. We don't really understand how it works, but it does so try it for yourself!