Bi-wire v's single with jumper leads.

While the back emf from the LF driver does create a signal that beats with the higher frequency components to produce distortion in the range of the HF circuit, I question the extent of that signal. Thevenizing the respective circuits (with a signal sources from the amp and signal source from the LF driver) results in a large disparity in loads. Unless the output Z of the amp and cable are significant in comparison with the Z of the HF circuit the amount of IMD should be extremely small. Most decent amplifiers and just about any cable at length less than say 20 feet present a Z orders of magnitude less than the HF circuit. While biwiring will affect the IMD caused by the LF driver signal, it is unlikely that the IMD thus generated is of any practical signficance in most instances.

Jams70: Put all the analysis aside and simply listen for YOURSELF.

I think biwiring works if you can filter the HF and LF before the speaker cables, or even before your power amp.

The ideal would be according to me:

LF-power amp- speaker cable-tweeter
pre amp <
HF-power amp- speaker cable-woofer

This being 1 channel, if you have 3 way or more then repeat for each.
I don't understand why some 3 way speakers have bi-wire option shouldn't they have a tri-wire set up.

Bi wiring will not always give you a better sound. It really depends on the speakers and it's cross over design.
If you really want to go the bi wiring route then you need to go what I call true bi wiring meaning 4 seperate runs to each speaker. The 2-4 design is a bit waste of time and might as well use single wired with jumpers instead.
Hope this helps.

Flashunlock "The 2-4 design is a bit waste of time and might as well use single wired with jumpers instead."

That couldn't be any further from the truth. There will of course be systems where conventional bi-wiring results in no audible improvement, but it's generally (in mid-fi & better systems) a very effective and impressive tweak.

To expand on what I explained earlier, 2-4 bi-wiring has the same effect as putting the crossover at the speaker terminals, rather than in the speaker, thus greatly reducing the distance traveled by the combined high & low frequencies.
Basic electronics will tell you that once any kind of filter exists in a circuit (eg a high-pass frequency audio filter as in a crossover), then the ENTIRE CIRCUIT is only capable of carrying what that filter allows.
As an analogy; if you put a 100 ohm resistor in line with 0.01 ohm/metre cable, the entire cable will have a resistance of about 100 ohms; the resistor dictates what that cable can carry.
Removing the jumpers and bi-wiring means the low-pass filter (for the woofer) acts on the entire LF cable right back to the speaker terminals, and same for the HF cable.