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One-way inter-connect cables?

post #1 of 28
2/25/12 at 1:56pm
Thread Starter 
Seriously. A friend of mine called me with a question that I could not answer.

He bought a pair of "premium" RCA->RCA cables (3ft.) at a local thrift store. $5. AudioQuest Evergreen, he says. But he is confused at the warning given on the package to "make sure the arrows are going FROM the output TO the input.

Can somebody please explain the theory behind this? Thanks.
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post #2 of 28
2/25/12 at 2:01pm
Quote:
Originally Posted by domino92024 View Post

Seriously. A friend of mine called me with a question that I could not answer.

He bought a pair of "premium" RCA->RCA cables (3ft.) at a local thrift store. $5. AudioQuest Evergreen, he says. But he is confused at the warning given on the package to "make sure the arrows are going FROM the output TO the input.

Can somebody please explain the theory behind this? Thanks.

To sell for a higher price.

Tell him to hook them up one way-then the "wrong way" and see if he hears a difference.

Or better yet-have somebody else hook them up each way-without the listener knowing what way they were hooked up-and see if he call tell a difference.

It's good that he got them at a thrift store-and did not pay good money for them.
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post #3 of 28
2/25/12 at 2:03pm
Quote:
Originally Posted by domino92024 View Post

Can somebody please explain the theory behind this? Thanks.

The only reason (my theory) is for the manufacturer and the retailer to make a profit.

My prediction...
This thread will become amusing.
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post #4 of 28
2/25/12 at 2:04pm
Quote:
Originally Posted by domino92024 View Post

...Can somebody please explain the theory behind this? Thanks.

Marketing department theory and nothing to do with R&D. Electrons can't read.
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post #5 of 28
2/25/12 at 3:08pm
Quote:
Originally Posted by domino92024 View Post

Seriously. A friend of mine called me with a question that I could not answer.

He bought a pair of "premium" RCA->RCA cables (3ft.) at a local thrift store. $5. AudioQuest Evergreen, he says. But he is confused at the warning given on the package to "make sure the arrows are going FROM the output TO the input.

Can somebody please explain the theory behind this? Thanks.

There's no "theory" behind this - it's just a silly label. There is no warning/problem with hooking them whichever way you want. This kind of labeling is somewhat common on "premium" cables (I've seen a lot of Monster cables with the same arrangement; AudioQuest is the more expensive version of Monster) - it doesn't do anything for you either way. If you really feel bad about it, hook them up following the arrows, either way you've got however many ounces of copper/whatever between X and Y sending your signal.

The marketing explanation has to do with some made-up Universe where physics is different and electrons behave in a different way. I'm sure if we had the ability to go into alternate realities and so on, we'd be able to demonstrate the effect. But in our Universe, it's not a problem.

Your friend did good at $5; I think these cables sell for $10/foot in most boutique shops (which is highway robbery by another name).
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post #6 of 28
2/25/12 at 4:10pm
Well it is possible there is Shield around twin coaxial conductors. The shield would be connected at one side the source side hence the direction arrows.
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post #7 of 28
2/25/12 at 5:29pm
Quote:
Originally Posted by m1abrams View Post

Well it is possible there is Shield around twin coaxial conductors. The shield would be connected at one side the source side hence the direction arrows.

But the shield of the inner coax's would also have to be hooked to the same "ground"-because we are talking about unbalanced cables here-not balanced.

And the outer shield would still have the signal on it-although no signal would be flowing on it, but it could act as an antenna.

And that would also assume that the source grounds are also properly connected to the chassis ground and that the device has a proper AC ground to do any good.

While this is common in balanced connections (I do it all the time) the shield is not part of the actual signal path.
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post #8 of 28
2/25/12 at 5:32pm
This is Kurts response (Owner of Blue Jeans Cable) to this potential variety of cable:

I wouldn't be so quick to assume it's a floated shield. I have seen a lot of different rationales offered for "directionality," none of which make a lot of sense, and without an explanation from the vendor as to what the arrows are purported to mean, or how the cable is internally wired, it's anybody's guess.

Telescoping a shield like this, incidentally, does not really work in unbalanced circuits. When it's done, the two RCA grounds are ordinarily connected by an inner conductor (that is, "balanced" type cable has been used to connect unbalanced gear), because if the cable doesn't contain a signal return path, the return can wind up being quite indirect, which often will result in a lot of noise as well as attenuation of the signal. It does work in balanced gear sometimes (not to reduce induced noise, but to eliminate ground loops), but that's because in balanced circuits there are two signal conductors and both are isolated from ground and have equal impedance to ground but opposite polarity. Anyhow: because there is a conductor in the cable joining the RCA grounds, noise on the shield CANNOT be isolated from either side--it just has a slightly more indirect, but still highly conductive, path to the one side than the other.

Telescoping a shield to reduce induced noise would be an unusual solution and will, in most circumstances, be ineffective. Shield effectiveness is dependent, among other things, on the shield being well-grounded, and removing the ground at one end of the shield will compromise shield effectiveness. In an unbalanced circuit you WANT the noise to shunt to ground, and anything which reduces shield effectiveness will result in more noise reaching the signal side of the circuit.

I have seen a lot of strange rationales given for directional arrows on various cable products. Some people think that copper "sounds" different when hooked up in the direction the wire was drawn, for example (which of course ignores the fact that the signal is alternating current and flows as much in one direction as the other). Some manufacturers put little RC networks into one end of the cable. The floated shield is one possibility, but certainly not the only one, and absent an explanation from Monster I wouldn't assume that that's what's been done here.

Kurt
Blue Jeans Cable
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post #9 of 28
2/25/12 at 9:48pm
Quote:
Originally Posted by m1abrams View Post

Well it is possible there is Shield around twin coaxial conductors. The shield would be connected at one side the source side hence the direction arrows.


That's most often what the arrow indicates...shield floating at one end. On some the arrow points to the floating end, on some the arrow points away from the floating end.

Whether or not this connection method has any merit is a separate issue.
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post #10 of 28
2/25/12 at 10:05pm
Thread Starter 
Quote:
Originally Posted by m1abrams View Post

Well it is possible there is Shield around twin coaxial conductors. The shield would be connected at one side the source side hence the direction arrows.

Two theory papers from AudioQuest (FWIW):

http://www2.audioquest.com/wp-conten...2/NoiseDis.pdf
http://www2.audioquest.com/wp-conten...011/12/DBS.pdf

Happy reading, y'all!
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post #11 of 28
2/26/12 at 9:11am
If the outer shield is only terminated at one end, it does not carry signal current and therefore the internal wire that is used as the "signal ground" does get protected from outside interference to a significant degree.

This can certainly be an advantage IF there is any significant source of interference in the first place. With some equipment, in some locations, it can offer an audible benefit in my experience compared to a simple coaxial cable.

With other equipment, in other locations, it seems not do so. There are an infinite number of variables, so the possibility of a difference is unpredictable. One factor that may be involved is exactly how the signal "ground" is floated within the equipment circuitry at either end.

One thing I am fairly certain of: anyone that says "cable A is better than cable B" without any qualifications is wrong. Cable A MIGHT perform better in a certain situation, and NOT in another location with different equipment. That has been my experience, anyway.

In any case, arrows on the outside may not mean there is a "floated shield". It may just mean they put them there.



P.S.- The Audioquest Evergreen definitely DOES NOT have 3 wires or a floated shield; it is a simple coaxial design, so arrows are meaningless if it has them.

The Audioquest Diamondback and King Cobra are the ones that I know have a floated shield and 3 conductors.




Quote:
Originally Posted by whoaru99 View Post

That's most often what the arrow indicates...shield floating at one end. On some the arrow points to the floating end, on some the arrow points away from the floating end.

Whether or not this connection method has any merit is a separate issue.
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post #12 of 28
2/26/12 at 9:20am
Quote:
Originally Posted by commsysman View Post

In any case, arrows on the outside may not mean there is a "floated shield". It may just mean they put them there.


Of course. That's why I said "most often" instead of "always".



Quote:
Originally Posted by commsysman View Post

.. One factor that may to be involved is exactly how the signal "ground" is floated within the equipment at either end.

Don't think this has any forbearance in unbalance equipment since signal return and signal ground are basically the same thing, not independent like the shield ground and hot/cold signal wires in a balanced system.
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post #13 of 28
2/26/12 at 9:51am
The reason I think that possibility is worth considering is that the "signal ground" conductor does carry signal current.

It cannot be truly at absolute ground at either end of the cable or that signal current could not flow and a signal would not actually exist. Equal current must flow in both the center conductor and shield of a coaxial cable at audio frequencies or there is no signal.

(This is unlike RF circuits and antennas, by the way, where the EARTH is the actual current return path)

There are different schemes for floating the signal ground in a circuit, and this affects how the two components interface with each other.

I think that these differences in grounding schemes sometimes causes some low-level 60 Hz current in the signal ground wire and is an issue that may possibly affect why cables perform differently. Maybe.




Quote:
Originally Posted by whoaru99 View Post

Of course. That's why I said "most often" instead of "always".
Don't think this has any forbearance in unbalance equipment since signal return and signal ground are basically the same thing, not independent like the shield ground and hot/cold signal wires in a balanced system.
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post #14 of 28
2/26/12 at 4:43pm
OMG guys, I installed my subwoofer Monster cable backwards when I 1st got it.....realized I hooked it up incorrectly when the LFE started coming out of the receiver.

True story.
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post #15 of 28
2/26/12 at 8:04pm
Quote:
Originally Posted by Yosh70 View Post

OMG guys, I installed my subwoofer Monster cable backwards when I 1st got it.....realized I hooked it up incorrectly when the LFE started coming out of the receiver. True story.

This tale-of-woe, and a desire to prevent a recurrence of similar "audio disasters" are no doubt the reason Yamaha developed the "even more idiot proof" subwoofer integrated receiver SR-300 and SR-301.
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post #16 of 28
2/26/12 at 8:14pm
Quote:
Originally Posted by domino92024 View Post

Two theory papers from AudioQuest (FWIW):

http://www2.audioquest.com/wp-conten...2/NoiseDis.pdf
http://www2.audioquest.com/wp-conten...011/12/DBS.pdf

Happy reading, y'all!

Note how they show an artists rendering of the scope waveforms. Why don't they just show the real scope picture?
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post #17 of 28
2/26/12 at 9:55pm
Thread Starter 
Quote:
Originally Posted by Glimmie View Post

Note how they show an artists rendering of the scope waveforms. Why don't they just show the real scope picture?

Yup. Maybe they didn't have a decent scope probe. Or a scope camera. I used to stand in my front yard and point my scope camera at speeding cars, like a radar gun.
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post #18 of 28
2/29/12 at 10:19am
Quote:
Originally Posted by domino92024 View Post

Seriously. A friend of mine called me with a question that I could not answer.

He bought a pair of "premium" RCA->RCA cables (3ft.) at a local thrift store. $5. AudioQuest Evergreen, he says. But he is confused at the warning given on the package to "make sure the arrows are going FROM the output TO the input.

Can somebody please explain the theory behind this? Thanks.

I'm not familiar with AQ's Evergreen line of interconnect cables, but that's likely an OK deal. Meaning that odds are that the likely new price at an official AudioQuest dealer was a lot higher than $5.

If cable directionality (the arrow pointers on the cables) does make any difference (and that's a very BIG BIG BIG if), it'd likely only be if one is doing rapid cable switching listening tests.

And I'd think that if a difference does exist (again a very BIG if), that it'd be so subtle the few could hear it, even with a very high end (expensive) music system.

I've only a few Audioquest interconnect cables and when I do use them, I completely ignore the "arrow pointers" on the cables.

Once cables are in place for a day or two, any possible polarization SQ effects (not even sure if this is a correct word) of the interconnect cable plastic/rubber would stabilize and not have any further affect.

Odds are HUGE that the science people on AVS will attack my above statements; suggest that I'm not too bright (to put it mildly); suggest that I do double blind listening tests; and so on.

Very little ever gets said in these AVS cable threads (interconnect cable or speaker cable), with the possible exception of possible differences being at most subtle and likely not worth bothering with given that there are likely other things to focus on in one's hifi/movie sound system.
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post #19 of 28
2/29/12 at 12:59pm
Quote:


Once cables are in place for a day or two, any possible polarization SQ effects (not even sure if this is a correct word) of the interconnect cable plastic/rubber would stabilize and not have any further affect.

How would a dielectric become polarised with an AC signal applied?

Quote:


Odds are HUGE that the educated people on AVS will attack my above statements;

ftfy.
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post #20 of 28
2/29/12 at 1:49pm
Thread Starter 
Quote:
Originally Posted by OtherSongs View Post

I'm not familiar with AQ's Evergreen line of interconnect cables, but that's likely an OK deal. Meaning that odds are that the likely new price at an official AudioQuest dealer was a lot higher than $5.

If cable directionality (the arrow pointers on the cables) does make any difference (and that's a very BIG BIG BIG if), it'd likely only be if one is doing rapid cable switching listening tests.

And I'd think that if a difference does exist (again a very BIG if), that it'd be so subtle the few could hear it, even with a very high end (expensive) music system.

I've only a few Audioquest interconnect cables and when I do use them, I completely ignore the "arrow pointers" on the cables.

Once cables are in place for a day or two, any possible polarization SQ effects (not even sure if this is a correct word) of the interconnect cable plastic/rubber would stabilize and not have any further affect.

Odds are HUGE that the science people on AVS will attack my above statements; suggest that I'm not too bright (to put it mildly); suggest that I do double blind listening tests; and so on.

Very little ever gets said in these AVS cable threads (interconnect cable or speaker cable), with the possible exception of possible differences being at most subtle and likely not worth bothering with given that there are likely other things to focus on in one's hifi/movie sound system.

Knowing he's not the inquisitive type, I suggested that he connect them as the manufacturer recommended, and just enjoy the music. He seems to be happy with his $5 purchase. AWTEW...

[BTW...I saw these cables for $26 at Amazon. ]
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post #21 of 28
2/29/12 at 2:04pm
I have a better question, WHAT THRIFT STORE? $5 good deal.
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post #22 of 28
2/29/12 at 8:58pm
Quote:
Originally Posted by domino92024 View Post

Knowing he's not the inquisitive type, I suggested that he connect them as the manufacturer recommended,

Very good suggestion to your friend.

Quote:
Originally Posted by domino92024 View Post

and just enjoy the music. He seems to be happy with his $5 purchase. AWTEW...

[BTW...I saw these cables for $26 at Amazon. ]

$5 vs $26 is a good deal!

Amazon prices vary a lot due to wide variety of 3rd party vendor pricing on the amazon site.

Nonetheless, $5 vs $26 seems a good deal to me!
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post #23 of 28
2/29/12 at 9:13pm
Quote:
Originally Posted by SAM64 View Post

How would a dielectric become polarised with an AC signal applied?

I've no clue, but I also said that that might not be the right word.

BTW, you misspelled it, it's polarized.

Quote:
Originally Posted by SAM64 View Post

ftfy.

I'll bite, what is ftfy?
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post #24 of 28
2/29/12 at 10:01pm
"Fixed that for you"
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post #25 of 28
2/29/12 at 10:34pm
Thread Starter 
Quote:
Originally Posted by MrBobb View Post

I have a better question, WHAT THRIFT STORE? $5 good deal.

Local one in Encinitas, CA. They were new in the original retail box. I guess they were part of a large donation of electronic stuff. It all went quickly.
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post #26 of 28
3/1/12 at 7:00am
Quote:


BTW, you misspelled it,

No, actually, I didn't.

Quote:


I've no clue,

clearly
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post #27 of 28
3/1/12 at 7:27am
Quote:
Originally Posted by SAM64 View Post

No, actually, I didn't.

If you live in the UK.
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post #28 of 28
3/1/12 at 8:01am
Quote:
Originally Posted by SAM64 View Post

How would a dielectric become polarised with an AC signal applied?



ftfy.

or how would it be polarized in the absence of a field?

The second audioquest PDF does contain a cable that has a 72v DC field across the dielectric, so technically they do polarize the dielectric in that specific cable.
I'm not saying it matters, just saying it's what they do.
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