Does speaker wire all have to be the same length? (1 Viewer)

[Todd K]

Is there any reason why the speaker wire running to my surround speakers has to be the same length? In order to conceal the wires, I will be running the wire to the surround along a side wall. Obviously, the distance to the surround farthest from that wall will necessitate a longer wire. So, should both surround wires be made longer so they are of identical length, or is it OK if the length to one is shorter than the length to the other?

Thanks for the input,

Todd K.

 

[David X]

Yes, it's ok if they are different lengths.

You might want to convince yourself first. There are different opinions on this.

-David

 

[Howard_S]

Todd. I would definitely not concern myself with the speaker lenghts for your surrounds. The surround information runs through so many processes before it reaches the sound is produced that it could be silly to be putting much thought on their lenghts. Besides, it's not like one is double the lenght of the other right? Even if it is it shouldn't cause a problem.

I would be more concerned with the fronts however.

 

[Chu Gai]

and for strike 3, it would take an enormous difference in distance before you'd hear anything. do what works in your particular situation.

 

[Glenn Overholt]

Without getting too technical, electricity moves at the speed of light, so if your fronts were on the moon.. Oh, skip that.

Blenn

 

[Todd K]

OK, I think I'm convinced. I had to be 100% sure, since I have some serious neuroses about such things. The difference in length for the surround cables wouldn't be more than the length of the back living room wall, which is something like 14 feet or so. And I guess since the lengths for the rear, center and fronts are all different anyways, and I've never noticed anything before, I should be fine. (The length of both the front cables are indeed the same.)

Thanks guys,

Todd

 

[Mark Austin]

With the surrounds it's not that big of a deal, differing lengths won't have much, if any of an impact. Now your mains would be a different story.

 

[James Elvick]

With the surrounds it's not that big of a deal, differing lengths won't have much, if any of an impact. Now your mains would be a different story.

Why?

James Elvick

 

[Mark Austin]

The ending damping factor is greatly influenced by the length and Ga. of cable you use.
Below is a damping calculator that illustrates the differences in damping factor between various wire lengths and guages.
http://www.eatel.net/~amptech/elecdisc/dampfact.htm

 

[JackS]

I'm using unequal lengths between my front speakers which are about 10ft apart. I have a 3ft run to the left, and about 9ft to the right. In the past, I have used equal lengths, but no longer think it's necessary. There is no audible difference that I can detect, and the instilation,in my case, is a little neater doing it this way. Also, a little cheaper this way, since you don't have to purchase un-needed wire.

 

[Saurav]

Without getting too technical, electricity moves at the speed of light, so if your fronts were on the moon.. Oh, skip that.

That's a response I've seen a few times, and it misses the point entirely. It's not about how long it takes the signal to get to the speaker. All cable has capacitance and inductance, in addition to resistance. For instance, good coax has about 20nF (or is it pF?) capacitance per foot. Capacitance usually acts as a low pass filter, rolling off the higher frequencies.
If your cable runs are of very different lengths, the amount of roll-off between the two speakers will be different. And AFAIK, human hearing is much more sensitive to differences than to absolutes. For instance, very few people would be able to listen to a tone and tell what frequency it was, but almost everyone can tell which one of two tones is higher pitched. Ditto for volume levels.
So, if you're using cable with relatively high capacitance, and if you have a gross difference between the two sides (say 50' for one and 100' for the other), and you listened really carefully, you could hear a difference. Like someone said before, for surrounds this isn't important. For mains, I probably wouldn't do it. YMMV.
Edit: Just to be a jerk... Electricity does not move at the speed of light in a copper conductor. It moves much slower, around 50% to 75% of the speed of light, I think. The electric field in the wire propagates almost instantly. And please don't ask me what the difference is, because this is all I remember from my electronics classes