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Author Topic: Speaker Wire shielded or not  (Read 14567 times)

Jonathan Johnson

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Re: Speaker Wire shielded or not
« Reply #10 on: September 16, 2013, 05:43:18 PM »

I'm beginning to suspect that the nearby high voltage transmission lines may be an issue. You will definitely want to use steel conduit wherever possible, but to minimize ground loops try to ground the conduit at only one end wherever possible. If you have concrete or steel structure that the conduit and boxes are fastened to, single-point grounding may not be possible.

The zip cord that you describe probably isn't twisted pair. It may be picking up induced current from the transmission lines which then energizes the voice coils in the speaker. Using twisted pair speaker cable may be a benefit.

For grounding issues, I'd suggest contacting Mike Sokol. He's a member of these forums and has done a considerable amount of research into grounding, ground loops, and reducing noise in systems. (Click on his name to view his profile or send him a message.)
« Last Edit: September 16, 2013, 05:46:11 PM by Jonathan Johnson »
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Stop confusing the issue with facts and logic!

Ivan Beaver

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Re: Speaker Wire shielded or not
« Reply #11 on: September 16, 2013, 05:50:05 PM »

If this statement is true, then it is coming from somewhere other than your PA system.
ACTUALLY-I had a case in which the front fill speakers were buzzing-even with the amps turned off.

You could even unplug the AC cables from the amps and the speakers were still buzzing.

It took me a little bit-but I found the problem.

It was a mounting screw in the 1/4" jack plate attached to the stage.  The 1/4" jack was not isolated from the plate and the screw was just barely touching the steel studs in the stage.

Come to find out that the stage "studs" were a couple of volts above the building ground-hence the buzz.

I moved the screw 1/4" and all was fine.
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A complex question is easily answered by a simple-easy to understand WRONG answer!

Ivan Beaver
Danley Sound Labs

PHYSICS- NOT FADS!

ProSoundWeb Community

Re: Speaker Wire shielded or not
« Reply #11 on: September 16, 2013, 05:50:05 PM »


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