Curious How These Nordost Speaker Cables Do What They Do

@williewonka 
sorry you thought my post bombastic :-$ perhaps I get a bit carried away when fundamental laws are ignored.

the current (i.e. energy), or maybe even the voltage, in the neutral (i.e. minus) conductor cannot possibly be the same as the signal conductor.

It cannot be otherwise. As you state, energy cannot be created or destroyed. It changes state in the load.

The work is done by V pushing I through the load. If you measure a loudspeaker circuit, very little V is lost from either amplifier terminal to the speaker. Almost all V is across the load. Power is V x I. If the current were different in each leg of the cable, energy would either be gained or lost.

Apply a steady 1kHz 1V signal to a speaker. Regardless of where an ammeter is inserted in the circuit, the RMS current is the same.

In a DC circuit, V and I are in phase. In an AC circuit, V and I are not in phase if there is any L or C.  Cable LRC change the phase and relative amplitude in combination with amplifier and loudspeaker LRC.

Phase angle is dependent on the difference between L reactance XL and C reactance XC, which vary with frequency. In cables like zip cord XL & XC may vary by a factor of 100 to 1. Some exotic cables XL & XC may vary by a billion to 1. XL can vary by a factor of 10,000 and more between zip cord and exotic cables. Exotic cables should endeavor to have less inductance, but some are worse than zip cord.

Asymmetric cables have a different L & C relative to parallel or woven and as such affect the current phase differently. These phase changes may be euphonious with some amplifier / loudspeaker combinations, not so much with others.

Some put sugar in coffee and prefer the 'sweetened' result.

One cannot, in absolute terms, say it is better [more accurate].

One can only say it is more accurate if one compares the source wave form to the resulting sound at your ear!

@almarg - I think the lightbulb analogy is not a great example because the bulb is connected between two terminals that are both carrying an alternating voltage/current - I agree in that scenario there would be the same voltage on the +ve and -ve conductors

However in an amp, only the "SIGNAL PATH" of the circuit carries the alternating voltage/current
- the "power rail" is always at some +ve DC voltage
- the neutral rail is always at zero volts.(or should be)

The output terminal of transistor or tube performing the amplification carries the AC signal
- but the neutral side of the amp's circuit remains zero volts

The neutral conductor in the speaker cable, being connected to the neutral rail, should be at zero volts - should it not?

 I can see there would be  "a flow of electrical energy" that is from +ve output terminal - via the loudspeaker and cable - returning to the amp's -ve terminal. But somewhere along the way power has to be converted/consumed and that means either the current or the voltage has to change - doesn't it?

Thanks

No, that’s not correct, Steve.

First, keep in mind that a voltage must always be defined relative to some point, i.e., it exists between two points. It is not meaningful to simply think that "the neutral rail is always at zero volts."

In the case of a light bulb the terminal that is connected to AC "hot" is at 120 volts relative to the terminal that is connected to AC "neutral," which in turn is at or very close to zero volts relative to earth ground. In the case of a speaker cable the + wire is at some voltage relative to the - wire, depending on the signal at any given instant, and depending on the design of the amp the voltage on the - wire may or may not be at zero volts relative to the amp’s circuit ground, or relative to AC neutral, AC safety ground, and earth ground. For example, "fully balanced" amps and bridged mono amps both have full amplitude signals on both their + and - output terminals, with the voltages on those terminals differing from each other simply in that they have opposite polarities.

The current that is provided to a speaker by an amp, as well as the current that is provided to a light bulb by the incoming AC, both result from a voltage **difference** that is applied between the two conductors. The fact that one conductor may be at zero volts relative to some reference has no relevance to that.

Also, ieales comment above that relates to this ...

If the current were different in each leg of the cable, energy would either be gained or lost.

Apply a steady 1kHz 1V signal to a speaker. Regardless of where an ammeter is inserted in the circuit, the RMS current is the same.

... is absolutely correct.

Best regards,
-- Al

@almarg and @ieales - thanks for taking the time to explain.

Cheers - Steve