I need help on directionality of speaker cables

Carl109,

If you would do a search there are abundance of details of skin effect that do occur in digital interconnects, be it SP/DIF or AES/EBU. This is just one out of the many references that describes this.

http://www.psaudio.com/products/xstream_digital_moreinfo.asp

You have to scroll down abit though. I didn't provide any links earlier as I thought nobody would be interested to have a look (since Bob didn't read the earlier link by Stereophile). And just if anyone wants to know more about skin effect, here is the description in Wikipedia.

http://en.wikipedia.org/wiki/Skin_effect

Probably your reference book doesn't mention anything on skin effect in digital cables? Anyways, the main question that remains is whether there is any direct correlation between AC(non-directional) and directionality in cables. There is no definite answer to that I would really like to know as well.

Ah yes Ryder, but from the Wikipedia link you posted: "The skin effect is the tendency of an alternating electric current (AC) to distribute itself within a conductor so that the current density near the surface of the conductor is greater than that at its core."

Even this notes that the skin effect is specific to AC current.

Transmission of digital data, as I quoted from the electronics text, is DC.

Put these two facts together and "skin effect" is not relevant to digital data transmission, and so cables for such DC digital data do not need to take it into account.

QED.

Wow, this thread got carried away down the wrong road.

As an EE, the way I see it is that cables with direction arrows on them are solely to get the shield grounded properly. End of story. If they have no shield, there is no good reason for the arrows that I can see.

Skin effect is a function of frequency so DC signals never see it.

Arthur

he 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,

Transmission of digital data, as I quoted from the electronics text, is DC

You are probably confusing the way Digital is represented in a drawing....most encyclopedia's and layman reference material incorrectly represents digital. When you see a typical analog waveform drawn with a "digital" stair steps superimposed that look like DC levels.... this is WRONG it doesn't exist like this.

Sorry but I studied digital signal processing and analysis in college...the whole subject has been badly dumbed down and leads to much confusion and fear of digital ( obviously a stair case is nothing remotely close to an analog waveform and hence the source of some of the malicious rumours about digital )

Digital data is sent as analog waveforms. Toslink Light is an alternating waveform as is the signal on an RCA coax or an HDMI cable. Typically all electronic devices used some form of MODEM between digital devices (Modulator and Demodulator; the digital data is encoded into some form of alternating signal often with a separate or embedded clock alternating signal to help in decoding the "states" into discrete "bits").

Aball, you are the one who first stated that the arrows were in the direction of the current! Surely, as an EE, you didn't mean that, but meant the direction of the signal.
As for the shield concept indicating the direction of the cable, well we covered that.
However, it is good to finally get an EE to set the record straight on direction of current in an AC carrying circuit.
Bob P.