The jumpers electrically connect the 4 posts, and reconnect the two internal halves of the speaker crossover. So with the jumper in place, you have essentially 2 binding posts, as they are electrically joined by the jumper. You can connect to either set, as they are joined. Most people will connect to the bottom posts, as the cable typically comes up from the speaker base. This is not a hard and fast rule, although your speaker manual may dictate which to use.