B-wire - four cables or jumpers?

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.

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.