My experience with three different models of Wharfedale monitors is that:
1) replacing the metal bars from the factory with jumpers improves the overall sound of the speakers
2) the metal in the jumper cables matters with silver tipping the sound up towards treble emphasis compared with copper
3) connecting both red and black speaker cable leads on the HF terminals has a similar overall effect as connecting silver jumpers, emphasizing treble frequencies, while connecting both speaker cable ends to the LF terminals will emphasize bass and midrange and slightly roll off treble
4) cross wiring the + and - leads to the HF and LF terminals affects soundstaging, adding more detail to and widening the stereo image, with the positive lead attached to the HF terminal of the speaker slightly emphasizing treble, (opposite of what is described above?) but not to the same degree as attaching both cable ends to the HF posts.
I found these results on all three types of Wharfedale speakers of different vintages and costs. Newer Wharfedales come with instructions on these various wiring configurations when using single wire cables.
I have tried all kinds of homemade jumpers and some cheaper commercially available versions. I am currently using some jumpers from AliExpress that are supposedly silver plated OCC copper with rhodium plated copper spades that cost between $11 and $45. These seem super well made and sound fantastic to my ears. The Worlds Best Cable jumpers mentioned in this thread from Amazon are supposed to be Canare wire, look well-made and are probably leaps ahead of the metal plates that come stock with many speakers.
YMMV
kn