# does the speaker wire for my surrounds have to be the same length?

Discussion in 'Beginners, General Questions' started by Mike Matthews, Aug 29, 2003.

1. ### Mike Matthews Stunt Coordinator

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one surround needs about 50 feet of wire, the other about 35. should i just have each one as 50 feet and tie up the slack of the one? i was told that it's better to keep the lengths the same, although i don't really know why

2. ### ColinM Cinematographer

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I wouldn't worry about it. Just be sure to use 16ga or better. I have 40 ft on one, 30 on the other - no big whoop.

3. ### AlbertA Stunt Coordinator

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I didn't worry about the lenghts.

Some think that the delay introduced by having cables of different lenght is detrimental.

However, we are talking about electromagnetic waves at this point, and in copper they pretty much travel at the speed of light. That means that in your case 50 feet vs 35 feet would mean a difference of 15 ns.

As an engineer, I would tell you that the delay in the signal is insignificant since various experimental results on human hearing have shown the treshold of human hearing to be much much more than 15 ns!

4. ### Mike Matthews Stunt Coordinator

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sweet - i'll save a couple bucks!

5. ### Bob McElfresh Producer

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We did the calculations on another fourm and decided that it takes a difference of 80 feet to create a 1% phase shift in the sound from 2 speakers.

But there is a slant/rolloff with long runs of speaker wire. Several speaker sites recommend the following guidelines for size vs length:

1-10 ft: 16 ga
11-20 ft: 14 ga
20+ ft: 12 ga

Most of us just buy a spool of good 12 ga wire and use it everywhere.

Home Depot has some decent stuff, and a lot of people like the Sound King brand from www.partsexpress.com

Good Luck.