I can't answer @chrisr question as a matter of science. I can say that the factory jumper cables that came with my Avantgarde Duos circa 2006-7 were quickly replaced with Cardas jumpers to match the rest of the speaker cable I used at the time, and when I went to a different speaker cable- K-S, the jumpers were part of the 'loom.' The initial upgrade from the stock jumper was significant; the subsequent change of cable more so, in my system.
