B-wire - four cables or jumpers?

I have a pair of speakers for which the crossovers are specifically optimised for bi-wiring/bi-amping (Von Schweikert VR5s). As the singal current reaching the speakers comes from an identiscl source, namely the amp teminals, what is the difference between running a second set of cables from the amp, as opposed to using jumpers between the input terminals on the speakers? It seems to my uneducated electronic mind that the only differnce is in the length of the second set, as the signal is merely taken from the speaker terminals, rather than the amp terminals.

If that is so, then what is the sonic (realtime audible) advantage in spending twice the amount of money to run two sets of cables from the amp?

This really puzzels me!
Brianjh, search the archives here and you will find most, not all, agree that biwiring is advantangeous. There is a good article on the technical aspect of biwiring over at Audio Asylum by Jon Risch. I personally believe it sounds better on my Proac 3.8s. You raise an interesting thought however. Should I spend a lot on a premium set of cables and use the jumpers, or use two sets of good cable? This is something we must decide for our own system. I have opted to buy two sets of used premium cables here at Audiogon at less than half retail. Good Luck!
And, if you'd prefer an accurate description of the effects of biwiring, see:

Another reason why one would use a bi-wire configuration with these speakers would be in the case of using them with a tube amplifier. Tube amps typically have a 2, 4, or 8ohm tap on the back for your speaker outputs. that would allow you to match the load of the bass drivers to say a 4 ohm tap on the amp, where the mids/higs portion of the speaker
are better matched to the 8 ohm output of the amp. The different taps on tube amps also have a different sonic characteristic typically due to the number of windings used
on the output transformers. Hope this helps..

Check out this article on pros and cons.

When you use one set of speaker leads all the current passes thru the same wires. When you split the leads for high and low frequencies, each carries only the current it uses because the high and low frequency drivers have different appetites for current. It is believed that separating the flows preserves the purity of the signal.
AS an aside-- Von S. uses Analysis+ Oval9 internal wireing. Does that tell you what brand you should be using? AND it should not be jumpers !!
Yes Rockvergo, I agree all the current passes down the cable. but the high and low frequencies are split at the crossover, not at the amp or the speaker binding posts. I know some say a low frequency signal will follow the line of least resistance, and that this is an arguement for mixing stranded and solid core conductors in the same cable. Hence it would, if this is really true, make sense that the second pair of a bi-wired set (the woofer pair)should be of a larger cross-sectional area (and therefore have greater current carrying capacity?) than the pair going to the mid/treble section. However, many very high quality cables do not do this, eg Nordost for one. And in any case, this could also be applied to the jumper leads.

So my basic puzzlement remains: if the current arriving at the speaker binding post is the same as that leaving the amp - which it is - then apart from the length, aren't the jumper leads simply acting as a second pair of cables in a bi-wired system?

I will check out the sites suggested by Bomarc and Audio_Buff, to see if these articles throw any light on this.
Ok, let's add this to the puzzle: electrical devices draw current when processing electrical energy. Assuming an inexhaustible supply and an amplitude of signal to process, the load dictates the energy flow. No load, no flow. This explains why your electric bill doesn't skyrocket when you have the lights off.

More to the point, do we believe that if the crossover channels all the current, that the hypothetically-unused current gets soaked up and converted to heat, or maybe sent to ground and otherwise wasted by the crossover? Sure the crossover is a load in its own right. However, it's is my understanding that although the crossover processes the whole signal, it only allows the energy/current to pass to the device connected to it. The "rest" of the current never gets a chance to exist because there's nothing to draw it.
Using jumpers is not Bi-wiring. The choice would be between four cables or a pair of single internally bi-wire cable. Between those last two comes down to cost. Four cables will cost more.

You are best off experimenting with this yourself. If you buy used cables, you can resell your left-overs after you decided what you like.
Hmm... it's a long long time since I did any physics, but I seem to recall being told that current is like water and finds its own level. The signal is "carried" by the current I suppose as a modualated sine wave and when it reaches the loadspeaker voice coil is converted back into mechaical energy which vibrates the diaphram and appears as sound waves. I guess the current per se keeps on flowing round the circuit provided the circiut is closed, ie the mains is switched on, and there's an input signal being created.

That sounds a bit crude, and I don't think it's quite right either. But, nevertheless, the signal arriving at the speaker binding post continues through the binding post down the internal wiring to the crossover. As I understand it, the low, mid, and high, frequencies are filtered and processed by the crossover and proceed to the respective drivers. So what's the point of having another long set of cables from the amp to the second set of binding posts on the speakers, when ostensibly just joining the two sets of posts by jumpers is serving the same function. In other words the signal starts at the amp, is carried to the upper binding posts on the speaker, and via the jumper to the lower binding posts. As far as I recall, because of the hydrostatic nature of electricity, there will be no diminution of current or signal at either set of binding posts. In each case the signal continues through the binding post via the internal wiring to the (in the case of the VR5s) two separate crossover boards, where its filtered (at 3khz and 300khz). I suppose what I am saying is that it seems to me that what happens at the amp end if two sets of cables per speaker are used, is the same as what happens at the speaker end, if jumpers are used: it just takes place at the end of the cable run instead of the beginning.

I've looked at the two suggested sites, but they don't, as far as my maths allows me to determine, address this question. Dielectric parameters etc should be virtually the same using jumpers because of their very short length and the fact they are in essance a continuation of the main cable.

If I had sets of identical cables and jumpers, I would experiement with great vigour! Unfortunately I don't, and here in the UK it's difficult enoough to find dealers willing to let you demo cables without a committment to buy one or another, let alone borrow them for this sort of thing.