Jumper interaction with 3 way speaker

Jumper or bar, no difference.

@audiosens - the littleJumper Bars are "generally" poorly designed and fabricated, because they are often not made from copper and plated with a metal that has poor conductivity.

You can purchase jumpers made from wire with either spades or banana plugs using various types of wire, but they are generally short i.e. 8 - 12 inches.

This is a very good set of jumpers for a resaonable price

1877Phono OCC Jumper (BFA)1 Jumpers (partsconnexion.com)

RE: Will the sound coming from the jumper also be sent a little to the midrange and more to the tweeter? 

The jumper simply conveys the same signal to the section of the internal crossover that handles the higher frequncies

Hope that helps - Steve

some recommend the main cables goes to the mid/high and the jumper to the bass...I prefer jumper to be identical to main, usually not an expensive purchase...(yes, i realize it can be)...

Better to get a second set of speaker cables