J

#### jneutron

##### Senior Audioholic

For cables, that is roughly 1/2 lightspeed.

However, the only thing that moves at the inherent propagation velocity of the cable is signal WHICH HAS THE VOLTAGE TO CURRENT RELATIONSHIP WHICH IS CONSISTENT WITH THE CHARACTERISTIC IMPEDANCE OF THE CABLE.

This means that for a standard zip cord with approximately 150 ohms of impedance, only signal with 150 volts per ampere will travel at the prop velocity. Since the load has an impedance of about 8 ohms, this means that a 150 volt signal will hit the load, but only 8 will get to the load, the remanining 142 volts are reflected to the source.

The settling time for this system is the important thing, not the length vs prop velocity..

Coiling a zip cord does not introduce further inductance. It is only when the two opposing conductors are seperated will coiling alter the inductance and therefore the coupling to external time varying magnetic fields.

Cheers, John