Do I really have to cross my cables at 90 degrees? - Page 2 - AVS Forum
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post #31 of 41 Old 01-05-2014, 09:51 AM
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[quote name="DonH50" url="/t/1509091/do-i-really-have-to-cross-my-cables-at-90-degrees#post_24162000"
Good luck proving the audibility of the effect. Other coupling factors (besides Lorentz force) tend to cause issues running parallel wires, but chances are unless you are doing live sound with a 100' snake running power, speaker, and mic cables in the same bundle, you won't hear anything.[/quote]
Even then it is a non issue.

For decades manufacturers have been making audio snake cables with mic and speakers in the same jacket. And then in most cases an AC power cable is either run right beside it or taped to the snake.

I have yet to run into a case that had any issues.

And when you look at concert sound you have mics and AC power run side by side for several hundred feet (300ish) with no issues. Of course there are no speaker levels in parallel with mics in large setups-except on stage.

I was in the PA rental market for about 25 years and never had an issue with mic cables/speaker cables/AC cables interfering with each other-at least that I am aware of.

Sure it is a good idea to separate them and have them cross at 90°, but it does not make any audible difference (that i am aware of anyway).

I could see a problem however with unbalanced cables and AC cables since the common mode rejection is not there as with balanced cables. But then shorter cable lengths would probably make a bigger difference.

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post #32 of 41 Old 01-05-2014, 02:41 PM
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I have had a few problems with long runs but have not done that sort of work for many years (save a church or two when I helped out). My example was more to show how unlikely such a problem is in a home scenario, not to imply pro systems routinely see such issues. Thinking back it is likely the problems I had back then were the result of a bad cable (generally broken shield) than the run itself. I most certainly didn't solve them by crossing cables at 90 degrees, that was not an option...

I have had hum and noise when light power cables were run with the audio snake, and even line-level runs to the amps on stage. That was a LOT of current, however, and I tend to think the problem was the light dimmers' switching noise.

I am not sure I have ever seen hum induced even in a home system from laying speaker or line-level cables along a power cord. The only time I can recall off-hand was when a turntable cable was bundled with a power cord.

"After silence, that which best expresses the inexpressible, is music" - Aldous Huxley
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post #33 of 41 Old 01-05-2014, 02:45 PM
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Quote:
Originally Posted by DonH50 View Post

I have had a few problems with long runs but have not done that sort of work for many years (save a church or two when I helped out). My example was more to show how unlikely such a problem is in a home scenario, not to imply pro systems routinely see such issues. Thinking back it is likely the problems I had back then were the result of a bad cable (generally broken shield) than the run itself. I most certainly didn't solve them by crossing cables at 90 degrees, that was not an option...

I have had hum and noise when light power cables were run with the audio snake, and even line-level runs to the amps on stage. That was a LOT of current, however, and I tend to think the problem was the light dimmers' switching noise.

I am not sure I have ever seen hum induced even in a home system from laying speaker or line-level cables along a power cord. The only time I can recall off-hand was when a turntable cable was bundled with a power cord.

 

Knowing the theoretical argument, I was initially slightly concerned when I was forced, due to space restrictions and physical layout of the back of the system rack, to run power and signal cables side by side. Zero hum. Even with MV turned up to max and ear against the speaker - zero hum.  

 

Other than anything else, I'd have thought that for most people, laying the signal and power cables at right angles to each other would usually be a practical impossibility.

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post #34 of 41 Old 01-05-2014, 02:53 PM
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I continue to be amazed and impressed by those who can hear what to me seem to be only theoretical issues. smile.gif Too many years sitting on the back row playing away, guess my ears are only good for music and not audiophile gear.

"After silence, that which best expresses the inexpressible, is music" - Aldous Huxley
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post #35 of 41 Old 01-05-2014, 03:19 PM
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Quote:
Originally Posted by DonH50 View Post

I have had a few problems with long runs but have not done that sort of work for many years (save a church or two when I helped out). My example was more to show how unlikely such a problem is in a home scenario, not to imply pro systems routinely see such issues. Thinking back it is likely the problems I had back then were the result of a bad cable (generally broken shield) than the run itself. I most certainly didn't solve them by crossing cables at 90 degrees, that was not an option...

I have had hum and noise when light power cables were run with the audio snake, and even line-level runs to the amps on stage. That was a LOT of current, however, and I tend to think the problem was the light dimmers' switching noise.

I am not sure I have ever seen hum induced even in a home system from laying speaker or line-level cables along a power cord. The only time I can recall off-hand was when a turntable cable was bundled with a power cord.
Most likely there were pieces of gear that had a typical "pin 1 problem" in which pin 1 was allowed to get inside the unit and the noise on the shield got on the ground buss.

Build the gear properly and that is a non issue.

Also consider that an live audio system (one that uses mics) has waayyyy more gain in it than a home theater system. Up to 40dB (give or take a bunch even 20dB ore more) which is 10,000 times more gain. So those system are much less "immune" than a home theater system.

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post #36 of 41 Old 01-05-2014, 06:31 PM - Thread Starter
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Originally Posted by Ivan Beaver View Post


Also consider that an live audio system (one that uses mics) has waayyyy more gain in it than a home theater system. Up to 40dB (give or take a bunch even 20dB ore more) which is 10,000 times more gain. So those system are much less "immune" than a home theater system.

Since I was the guilty one who started this thread, I want to end my piece here by quoting Ivan, above. As I said, my design was for myself, not for live performance. Ivan is right.
Second, theory in physics is not "theoretical" in the way lay people use that word. But I think most people in this thread understood that. And they also got it that "physics is the law", as Elon Musk said it in an interview today.
Third, you also all understood that the next phase of this inquiry is this: to prove that in a home listening environment, you can hear a difference. That is when it gets murky. But you do not have to do what I did. You can test the hypothesis (NOT THEORY) that crossing your wires can make a difference. When you cross 2 wires, elevate one with a slice of a 4x4 lumber. It may be ugly, but that should not matter to you at this time. After your little experiment, please continue to post the results. However, make sure that you include a description of your test instruments. I.e., your stereo equipment. Please no Bose jokes!

And finally, I did this design to be CONSISTENT with my listening instruments. They not only sound excellent, but they do share my aesthetic sensibilities in the way they look. Please look at the photos again. But of course, like some of my clients, we are all different in that regard.

Once again, thank you for commenting. It could have been lonely otherwise!
Cheers!
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post #37 of 41 Old 01-05-2014, 06:45 PM
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Quit the wordplay and set up and do some good measurements; it's not all that difficult to measure far more sensitively than we can hear which will eliminate all the subjective bias.

I have also used combination snakes to drive my PA in some venues over many issues with zero audibility issues, and I so far see no reason to believe that your issue will ever prove audible in domestic situations; tested at home including measurements as I believe in preventative maintenance.

All I see here is you trying to generate some interest in what will no doubt turn out to be an expensive gimmick item to sell to gullible audiophools by using what to them will be confusing, but conceivably 'believable' to them terminology and electrical theory.
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post #38 of 41 Old 01-05-2014, 06:49 PM
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Quote:
Originally Posted by Ponchit View Post

. You can test the hypothesis (NOT THEORY) that crossing your wires can make a difference. When you cross 2 wires, elevate one with a slice of a 4x4 lumber. It may be ugly, but that should not matter to you at this time. After your little experiment, please continue to post the results. However, make sure that you include a description of your test instruments. I.e., your stereo equipment. Please no Bose jokes!
Maybe it would help if you gave a suggestion as to what type of wires (ie both speaker-both signal-speaker and signal-Ac and so forth) you suggest would give the biggest difference or to hear the most effect.

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post #39 of 41 Old 01-05-2014, 07:03 PM
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post #40 of 41 Old 01-05-2014, 07:20 PM - Thread Starter
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Quote:
Originally Posted by Ivan Beaver View Post

Maybe it would help if you gave a suggestion as to what type of wires (ie both speaker-both signal-speaker and signal-Ac and so forth) you suggest would give the biggest difference or to hear the most effect.

Hi Ivan,
My first priority is crossing signal vs. power, then signal vs. speaker wires. Lastly, I will also test speaker wires crossing power. Then compare all of these vs. the same wires but parallel and touching.
In describing your instruments, I forgot to include the type and quality of cables used and their connectors.
Keep me posted. Thanks.
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post #41 of 41 Old 01-05-2014, 07:29 PM
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Quote:
Originally Posted by Ivan Beaver View Post

Quote:
Originally Posted by DonH50 View Post

I have had a few problems with long runs but have not done that sort of work for many years (save a church or two when I helped out). My example was more to show how unlikely such a problem is in a home scenario, not to imply pro systems routinely see such issues. Thinking back it is likely the problems I had back then were the result of a bad cable (generally broken shield) than the run itself. I most certainly didn't solve them by crossing cables at 90 degrees, that was not an option...

I have had hum and noise when light power cables were run with the audio snake, and even line-level runs to the amps on stage. That was a LOT of current, however, and I tend to think the problem was the light dimmers' switching noise.

I am not sure I have ever seen hum induced even in a home system from laying speaker or line-level cables along a power cord. The only time I can recall off-hand was when a turntable cable was bundled with a power cord.
Most likely there were pieces of gear that had a typical "pin 1 problem" in which pin 1 was allowed to get inside the unit and the noise on the shield got on the ground buss.

Build the gear properly and that is a non issue.

Also consider that an live audio system (one that uses mics) has waayyyy more gain in it than a home theater system. Up to 40dB (give or take a bunch even 20dB ore more) which is 10,000 times more gain. So those system are much less "immune" than a home theater system.

Hmmm... I suppose the pin 1 issue could have been it but I really do not think so. That is a known and easy to find problem. In a couple of cases I think I just had bad grounds (swapping cables/feeds fixed it) and in the light power example I think it really was noise on the light runs. I ended up separating the snake from the light feeds to solve it. Of course, that does not in any disprove a lack of proper shielding, whether wrong pin 1 connection unbalancing the runs and providing a poor signal return or something else.

On gain, yes, except for systems using phono stages. But most home systems don't run phono lines along side power lines.

Nit-picking aside, I think we are in agreement that crossing all wires at 90 degrees in a home, or pro, system is not a requirement.

"After silence, that which best expresses the inexpressible, is music" - Aldous Huxley
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