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Message: <blockquote data-quote="Dan Mortensen" data-source="post: 83200" data-attributes="member: 2826">Re: AC and signal cable of whatever typeAaron's post frankly gobsmacked me, and in addition to replying here, I asked our local AES Committee the question "The console uses AES50 on Cat5e cables; is there an issue with running those cables next to twisted pair AC cables for a couple hundred feet?" as well as providing a link to this thread and a little background info.There are some pretty heavy theoretical hitters on our Committee, and Rick Chinn was the first to reply.  His response in its entirety:"the cat5 business is pretty well defined at the hardware level, so it shouldn't be influenced by stray fields from AC cabling. you should be careful, however, to not wrap the cat5 around something ferrous, or subject it to sharp bends."Microphone cables, can be affected, but I think there is a greater risk from current induced into the shield conductor that flows into a piece that has a pin 1 problem."At the WAMU theater, I assisted Bill Whitlock in solving a hum problem they had. The AC cables (three-phase, Y) were tossed into a trough, and the mike snake went into a separate trough. There was a significant amount of ground current flowing in the neutral of the power system."My recall is that this turned into a loop area problem, and we solved it by putting the mike snake in with the AC."The same loop area problem makes a good case for running your console's AC line alongside the mike snake. the caveat about mike cables and AC cables comes from following the lighting company's feeder lines, which likely have spikey nasty stuff from thyristor dimmers all over it. That stuff is not good for your audio. as usual someone simplified it to include ALL ac wiring, which just isn't so."And there you have it. Knowing Rick and his background and experience, and barring new evidence to the contrary, I consider this issue closed and will continue doing what you saw in the earlier post.And as a related aside, if you ever have an opportunity to hear Bill Whitlock speak about grounding, loop area, etc., you should take advantage of it.Edit: A couple people wrote about what happens when 1) you kink a Cat 5 or other digital cable, and 2) wrap an AC cable with data cable:1) "it can change the impedance characteristic and cause reflections which turn into data errors. Same for wrapping it around something ferrous (like a stage leg)"2) "Wrapping the entire cable with all conductors should not affect data, audio or bandwidth since that would be common mode filtering.  Like a common mode toroid."If there are other paths external to the cable, things may be different."Each twisted pair of Cat 5 is balanced, too.</blockquote>

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