Although these cables could certainly be used to bi-wire, that wasn't the concept here. As I understand it, there are four 4 gauge conductors woven together. They are obviously thick and heavy. So there are spades on one pair and banana plugs on the other. You probably couldn't get those connectors on two cables. But you can attach the spades first and then the banana plugs. The result is two 4 gauge cables on each terminal.
As for sound, since it was the only way we had them set up, I don't know how they might have improved the sound. With a new DAC, new amp and new cables involved (new to us), I don't have any way to know what contributed what to the sound. But the synergy was excellent.