Biwiring your loudspeakers can really make a difference, most people agree on that. But people seem not to agree upon whether the effect is good or bad
Biwiring means using separate cable runs for the tweeter and woofer of a loudspeaker in which the cables run in a uninterrupted length from amp to speaker. Incidentally it is not called biwiring if there is just one cable that is being split right before it connects to the speaker.
Alternatively using a biwire cable that has 4 connections at both sides, you can also connect separate amplifiers to the woofer and tweeter, and this is called bi-amping. The cable itself would then be called “shotgun”.
If you have a biwire connection but are using single wire cable, just try running two sets of the same cable. You’ll find that biwiring makes the soundstage larger, and gives more air to instruments within the stage. I quite like this effect but some people find this unnatural and maintain that the stage should not be any higher than it would be if the performers were in your room themselves.
To me the effects of bi-wiring sound as if the speaker’s drivers have been liberated, them no longer being modulated by each other, or at least less so. The effects can be observed with any speaker that I tried: B&W Nautilus 804’s portray the same improvements as a pair of Apogee Duetta Signature magnetostatics, and I hear the same improvements with any cable, as long as the same cable is used for the comparisons.
Please note: it’s very important for the high-low coherence that you use the same cable on the low and on the high connections. Otherwise you might get disjointed, out of time bass and/or forward highs. It is sometimes claimed that the perceived larger soundstage is actually caused by phase problems introduced by differences in the cables for high and low. While this can certainly be true if you use different kinds of cables for low and high, it is absolutely not the case if you use identical cables of the same length or a biwire cable that consists of identical wires.
Now, whether you will prefer biwired speakers over the same speakers single wired is completely up for debate and very much a matter of taste.