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Different Speaker Cable Lengths

SimpleTheater

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I've heard lots of people try to answer this question, so it's refreshing to see the Scientific Audiophile tackle the issue of having different lengths of speaker cable using math and science..

*WARNING* Very large numbers are used.

 

DeLub

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:)

Assuming his speeds are correct (didn’t check) this just means that one speaker will start 1/ 152,964,970,608,384,000 of a second earlier. No way this is audible. But if you want to compensate, you have to move your speaker 174,949,632,000 / 152,964,970,608,384,000 inch backwards (1.14… * 10^-6 inch). Good luck :)
 

Apesbrain

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Within reason, it makes no difference. Assume one speaker cable is 10 feet long and the other 20 feet long. Electricity will travel 10 feet in 10 nanoseconds. A 10 nanosecond difference at the speed of sound is 13/100,000 of an inch. There is no way your speakers are placed exactly equidistant from your listening position to that degree of accuracy. In fact, your ears are not aligned that closely on the sides of your head!

"I strongly recommend First Run Copper..." - Pfft.

That said, I'd always get the same lengths to make it easier to resell or to use in another application.
 

artburda

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If I remember correctly, Dr. Tist explained at a seminar in Europe that elecricity can travel faster through first run copper cables than regular off the shelf cables. So, you could try using one first run copper cable to compensate for the different lengths, if you absolutely cannot use the same length for both speaker cables.
 

raindance

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If I remember correctly, Dr. Tist explained at a seminar in Europe that elecricity can travel faster through first run copper cables than regular off the shelf cables. So, you could try using one first run copper cable to compensate for the different lengths, if you absolutely cannot use the same length for both speaker cables.
Haha Haha! :D
 

LTig

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I've heard lots of people try to answer this question, so it's refreshing to see the Scientific Audiophile tackle the issue of having different lengths of speaker cable using math and science..

*WARNING* Very large numbers are used.

His conclusion :facepalm: - it's a joke, or isn't it?
 

DonH56

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pkane

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His conclusion :facepalm: - it's a joke, or isn't it?

I’m having problems converting inches to miles, but would I need to move one speaker to the moon or further out to compensate for 1 inch difference in cables? Just trying to figure out new room layout…
 

DonH56

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I have not watched it (and probably won't) but maybe he meant "mils"? Or mm?
 
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SimpleTheater

SimpleTheater

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I’m having problems converting inches to miles, but would I need to move one speaker to the moon or further out to compensate for 1 inch difference in cables? Just trying to figure out new room layout…
Exactly. The math is clear, different speaker cable lengths create a time phase mismatch so severe there is no point in trying to fix it. Electricity is just too fast. I’m not clear why @DeLub is double checking the math, why do extra work when the video clearly shows everything visually.
 

restorer-john

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My pairs of speaker cables are exactly the same length and always have been. Even if that means laying the excess behind the cabinet if the installation was not symmetrical with the gear.

It's a variable I don't want to think about. :)
 

escksu

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I've heard lots of people try to answer this question, so it's refreshing to see the Scientific Audiophile tackle the issue of having different lengths of speaker cable using math and science..

*WARNING* Very large numbers are used.


No, he got it all wrong!

This is NOT speed of electricity, its EM wave in a wire. Btw, EM speed is affected by your insulator, not the wire.

Electricity is your voltage and current, current is electrons and electrons moves very slowly through a cable (drift speed). This is what drives your speakers.

So, why does it appears instant when drift speed is so low? Think of your wire as a pipe (filled with water). Then a water pump is attached to 1 side. When you turn on the pump, water flows and pushes the existing water out. The wire is filled with electrons.
 

amper42

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I replaced 20 year old inexpensive 14 gauge speaker wire with Belden 5000UP 12 AWG today. Both runs are 10 feet long to left and right speakers. I couldn't tell an audible difference in sound after the replacement, but the Belden 12 AWG certainly doesn't bend as easily as the old 14 gauge wire.
 

pkane

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Exactly. The math is clear, different speaker cable lengths create a time phase mismatch so severe there is no point in trying to fix it. Electricity is just too fast. I’m not clear why @DeLub is double checking the math, why do extra work when the video clearly shows everything visually.

It's OK to be skeptical, like a lot of people here are. But doubting Math.... man, that's on another level altogether. I hope these "skeptics" can figure it out sooner than later. Connect the dots, so to speak. Lift the veil. Open their eyes. The truth is out there, and all will become clear, eventually. One can only hope :)
 

escksu

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It's OK to be skeptical, like a lot of people here are. But doubting Math.... man, that's on another level altogether. I hope these "skeptics" can figure it out sooner than later. Connect the dots, so to speak. Lift the veil. Open their eyes. The truth is out there, and all will become clear, eventually. One can only hope :)

Read my post, the video is wrong.
 

DeLub

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Exactly. The math is clear, different speaker cable lengths create a time phase mismatch so severe there is no point in trying to fix it. Electricity is just too fast. I’m not clear why @DeLub is double checking the math, why do extra work when the video clearly shows everything visually.

I'm not doubting math at all, I'm just doubting the way the youtuber applies math. You can do all your divisions correctly, but if you should have been multiplying, you will still end up with the wrong answer. And that's what I'm saying: his reasoning is flawed.

Let me try explaining it differently without doing any calculation with these large numbers. Electrons travel at very high speed through the cable; sound travels at relatively (compared to the speed of light) slow speed through the air. The extra length the electrons have to travel in one cable will cost a certain amount of extra time. Since the speeds of electrons is very high, this will cost only a very small amount of time. Because the speed of sound is slower, in this same amount of time the traveled distance by the sound in the air is smaller. This means that if you want to compensate for extra cable length, you would have to move your speaker back a certain distance that is smaller then the difference in cable length. ... and not larger like the conclusion of the youtube video. (The calculation I did in my previous post for a difference in cable length of 1 inch.)

Let's approach it from a yet different point of view (including math :) ). Let's say I'm totally convinced by the video. I bought the recommended brand of loudspeaker wire and did my best to cut it into two exactly equal halves. And I was quite successful! I measured the difference between the two cables, and it is only 1/1000 of an inch! Impressive wire cutting, right? Now let's see how much I have to move my speaker to compensate for this 1/1000" difference. Let's do the same math as in the youtube video but instead of 1 inch we take 1/1000 of an inch.

- Electricity travels 152,964,970,608,384,000,000 1/1000 inches per second
- Sound travels 174,949,632,000,000 1/1000 inches per second
- Let's substract: electricity has jumped ahead 152,964,795,658,752,000,000 inches

Wow! that's even a larger difference than in the youtube video for a difference of 1 inch. (note btw that his substraction is off. he forgot three zeros at the end)

This should clearly be a trigger to note that his logic is wrong: a smaller difference in cable length, can never lead to having to compensate with a larger distance between speakers.

And what about the wire used inside the speaker? If there's a difference between two speakers, I cannot compensate... and what about a difference in length between the wire running to the woofer and the wire running to the tweeter? Oh man...

(Also not that I'm not looking at other things like phase and resistance of the cable and things like that. Just like the youtuber doesn't.)
 

Blumlein 88

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I'm reminded of a goofy way to make a delay line for rear speakers published in Speaker Builder mag way back in the 80's. Fellow put a small microphone in the end of a small tube. Put a small earphone in the other end. The delay was acoustic by wrapping this small tubing in a bundle that was however many feet was needed for the delay. 32 feet for 32 milliseconds roughly. Amp the microphone output feed to the rear speaker amps.
 

DeLub

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And at the risk of rambling on:

Another point showing the flawed logic is the incorrect use of units: if you subtract one speed in inches pers second, from another speed in inches per second, you end up with a speed difference in inches per second and not with a distance in inches.

If one car is driving 50 miles per hour, and another car is driving 40 miles per hour, and I subtract those, I get a speed difference of 10 miles per hour. Not a travelled distance of 10 miles.

Basically what he did was calculate the difference between the speed of light and the speed of sound in inches per second... nothing more.
 

restorer-john

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I'm reminded of a goofy way to make a delay line for rear speakers published in Speaker Builder mag way back in the 80's. Fellow put a small microphone in the end of a small tube. Put a small earphone in the other end. The delay was acoustic by wrapping this small tubing in a bundle that was however many feet was needed for the delay. 32 feet for 32 milliseconds roughly. Amp the microphone output feed to the rear speaker amps.

In the early 80s I used BBD ICs to do the same. :) By 1985 we had DSP and it could all be done easily.

I still reckon the easiest and most effective rear back in the day, was the old 'matrix' style difference signal sent to a pair of series connected rears as was done on a heap of early 1970s recievers for a speakers "B" option.
 
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