Pnjcic, Timrhu is probably right if they haven't gone through break-in. That is, they could sound somewhat horriible before break-in. But you probably know that. I wanted to try bi-wire against the recommendation of the manufacturer of my cable. I had previously started a thread asking as to the merits of bi-wire and there was no consensus. Since I seem to like to learn things the hard way, I tried a bi-wire set, wasn't thrilled, but let them break in. The manufacturer had included a set of straps because he was confident that I would not like the bi-wire. After about two weeks of break-in on the bi-wire set, I called him. At first he said to stack both terminations at speaker end on one set of speaker binding posts and add the straps. Then he said I could leave the bi-wire configuration as it was and simply add the straps. I did, and even though the straps weren't broken in, There was imediate improvement. It was as though something was wrong with the bi-wire configuration, and now, strapped, everything was right. I don't know why this is, but a wild guess is that it has something to do with the speaker crossover and some interaction with the signal which causes non-linearities. The crossover likes to be strapped (or biamped. It likes biamping, too.) Maybe this is just my speaker and not true for yours. But when I learn things the hard way, things stick.
If you could strap them with the same cable as your speaker cable without a lot of cost, couldn't hurt to try it.