I need help on directionality of speaker cables

Quoting directly from "Electronics for Dummies" page 222, here's a bit on digital waveforms...

"Digital Waveform: A DC signal that varies between no volts (low) to some pre-determined voltage (high). The digital circuitry interprets the timing and spacing of the high and low marks."

I've also confirmed that the current carried to the speakers is indeed AC.
I'm still trying to find something difinitve regarding the signal from source (eg CD player) to amp.

'Before this I had known that there must be some current to transport those bits(information) to the next stage.'
There is current to transport the information and it is DC. The signal is essentially varying voltage representing the numbers and these stream in at a fixed rate. The current is extremely small and in one direction, which might explain why direction might count for digital transfer of info.

'Your argument is that AC is non-directional. If that's the case, how do we explain on the findings by Robert Harley in Stereophile? My logic is simple. If what he wrote is true, then this will apply to speaker cable as well. By the way, it's AC current in speaker cables am I right?'
I haven't read the article, but if he is referring to the digital cables then we have established that perhaps direction does matter with DC.
All explanations that have to do with direction of current on cables carrying alternating current stand on very shaky ground, especially for non shielded cables.

'It's interesting to note of Russ Andrews claim of having verified the benefits of cable directionality with their engineers using advanced equipment and technology, but unfortunately didn't provide any technical evidence to back that up.'
I guess they feel that we wouldn't understand the sophistry?
Respectfully, Bob P.

My understanding was that audio signals could be carried as DC, but that AC was required for speakers to allow them to vibrate in piston fashion.

They could be carried as DC but they are not (in fact the sound you hear is alternating compression and dilatation of the air in your room....there is no stream of particles reaching your ears...the air just jostles around and you pick up these vibrations).

DC is used in power supplies but 99.99% of everything that involves information flow uses either AC or EM waves. Digital signals are transmitted in much the same way as analog but at much much higher frequencies...some kind of an alternating waveform (modulated by digital information to create a set of clealry distingusihable digital states that can be decoded at the receiveing end into the same stream of mathematical bits).

In the transmission of the signal in digital cables, electron travels down the cable at the frequencies used by audio/video signals. The higher the frequency of the signal, the more this signal is pushed to the surface of the cable, and the skin of the conductor itself carries a considerable portion of the signal. This phenomena which is called skin effect is a tendency for AC current to flow mostly near the outer surface of the solid electrical conductor at frequencies above the audio range.

In skin effect, the effective resistance of a wire is increased for AC current at moderate to high frequencies compared to the resistance of the same wire at DC current and low AC frequencies. In other words, both AC and DC current exist in digital cables.

I think the issue we need to be certain of here is whether we can really correlate AC current, which is non-directional, to the debate of directionality of cables. There may be other variables that may be overlooked.

On a separate note, I have always followed manufacturer's recommendations and never reversed the directionality of interconnects all this while but have once reversed my speaker cables for the sake of experimenting. Frankly I'm not so sure. I thought it sounded little messy, but then maybe it's in my head.

I guess we can kill off this discussion now for what could be just a simple question to the poster.

"In the transmission of the signal in digital cables, electron travels down the cable at the frequencies used by audio/video signals. The higher the frequency of the signal, the more this signal is pushed to the surface of the cable, and the skin of the conductor itself carries a considerable portion of the signal."

Ryder, where is this info from? The reason I ask is that a digital signal, by it's very nature, doesn't have frequency in the way analog signals do. As I've quoted above from a reputable book on electronics, a digital waveform is a DC signal that varies between zero volts and a max volts, with no in-between.
Skin effect, whilst it exists in analog transmission (especially video), is not relevant in digital data. That's why HDMI and digital RCA cables don't need to be silver-plated copper. The bitstream of digital data is either 0's (zero volts DC) or 1's (eg. +5 volts DC). The quality of the cable will impact on how much data loss or errors occur, and can cause timing errors, but it isn't carrying any frequencies as such in terms of audio or video frequency.

The only time you really need to consider the 'skin' effect is when using analog video, such as S-video, component etc.