Immediately REMOVE those terrible pins that ProAc provides as jumpers and buy yourself a set of real terminated jumper cables, either spades or bananas, whichever your actual speaker cables aren't. The pins are really crappy and I kept losing mine whenever I switched cables--they just fell out onto the carpet and were lost for hours. I use some Transparent jumpers w/spades, but have also tried some Analysis Plus jumpers w/bananas. Both immensely easier to use and better connections all round. Of course, as others have said, actually biwiring your speakers is another option.