Bi-wiring speakers

Bi-wiring can indeed produce a difference, and in some cases a significant improvement. But the speakers that improve most from bi-wiring from my experience are some of the British small monitor speakers where they have tried to achieve transparency at a low price point from using a minimalist cross-over. Speakers like Thiels however involve a lot of effort in the cross-over to get it right and nullify the benefits of bi-wiring. Shotgun bi-wiring is the main area where you get different results, not necessarily a better one - principally because you are really changing the load seen by the amp.

The audible benefits or otherwise of bi-wiring are very dependent on the speaker and so it is easy for one person to experience a significant benefit and another to hear no difference. The key reason why a benefit can accrue from bi-wiring is simply due to the fact that bi-wiring a two-way speaker provides star-earthing at the amp, rather than at the cross-over. If the connection between the earth point on the cross-over and the amp has no resistance (impossible) then there is no benefit to bi-wiring. The size of the benefit depends on the potential (pardon the pun) for the current that is created by a slightly floating earth (when not bi-wiring) to cause audible interaction between the drivers. This depends on cross-over design and the impedence characteristics of the separate drivers. Double bi-wiring is not necessarily an improvement - it provides a different resistance and capacitance for the amp than single (or internal) bi-wiring and this may or may not be beneficial.