A few of us Salk owners have found out the Cardas copper jumpers supplied deteriorate over time, and really negatively affect the sound. We have all since switched to bi-wiring, or in my case, I had my speaker cables made with jumpers built in.
If you have jumpers that have deteriorated, it's best to use the top terminals as the mid/high frequencies are more easily negatively affected. I have found treble to be most sensitive to anything metal in cables, jumpers, connectors, so I always keep the path to the tweeters as simple as possible. I always use the top terminals first.