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Question Cable Length Difference

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Longchops

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Oct 15, 2020
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Greater impedance won't slow the electricity down!
Hmm ok. Resistance/type of medium does though definitely....where does the 80% of the speed of light measurement come from btw? Quite interested in this topic!

An enhancer must be a necessity for live shows. If you could imagine at the average festival it would surely not be uncommon to have several miles of cable and various speakers hundreds and thousands of metres apart which would surely present a big muddy wall of noise were some delay based trickery not used.

We use other delay based effects in pro audio too. You've probably heard of a Phaser ( 0.1ms Delay) Flanger (5-15 ms Delay) and Chorus (20ms delay)

These are seriously microscopic times, but each effect is very distinctive. A Phaser is basically a 10,000th of a second delay and is of course very noticeable, so I'm guessing 1/40,000th of a second also would be very noticeable too, I wonder if the human ear is much more responsive than we are giving it credit for in this calculation?
 

abacus

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Sep 24, 2008
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A live concert has nothing in common with a Hi-Fi/AV system as far as cables are concerned.

In a live concert the mixing/control desk is always away from the stage so that the engineers can monitor the sound and make adjustments to suit. (So long as the cables are plugged into the right connections there will be no problems unless the engineer doesn’t know how to do there job)

Effect processors have nothing in common with what’s being discussed in this thread as it is an addition to, not a correctional device.

Bill
 

12th Monkey

Well-known member
Aug 31, 2015
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Are these more to do with the delays due to speaker placement - in other words it's the delay in the air that is being affected, not the delay in cable length.

I seriously doubt that such small delays are audible though - sound travels around 350m/s, so a shift of 3.5cm in the position of your head is the equivalent of a delay of 1/10,000th of a second. Moving my head that much nearer to one speaker makes no difference to the sound I hear, so I think we're barking up the wrong tree here!


If different materials conduct at different speeds, I doubt that speed is affected by frequency.
 

Longchops

Well-known member
Oct 15, 2020
59
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Are these more to do with the delays due to speaker placement - in other words it's the delay in the air that is being affected, not the delay in cable length.

I seriously doubt that such small delays are audible though - sound travels around 350m/s, so a shift of 3.5cm in the position of your head is the equivalent of a delay of 1/10,000th of a second. Moving my head that much nearer to one speaker makes no difference to the sound I hear, so I think we're barking up the wrong tree here!


If different materials conduct at different speeds, I doubt that speed is affected by frequency.

I honestly have no idea, probably a combination of both tbh, next time I go to a gig (probably 2022 at this rate :LOL: ) I might have a word with the sound guy

As I said, a delay of 1/10,000 of a second producers a phaser effect and it is indeed very noticeable. Our ears are absolutely that sensitive. Interesting I can achieve it by tilting my head! And an enhancer is indeed a correctional device Bill, as well as being an effect. Its to stop the spread of bass and treble frequencies through air as I explained.

I believe this is relevant to the topic because you would probably feel the delay before you heard it, when the the difference between speaker cables reached this theoretical limit we are discussing
 

shadders

Well-known member
Nov 19, 2009
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Hmm ok. Resistance/type of medium does though definitely....where does the 80% of the speed of light measurement come from btw? Quite interested in this topic!

An enhancer must be a necessity for live shows. If you could imagine at the average festival it would surely not be uncommon to have several miles of cable and various speakers hundreds and thousands of metres apart which would surely present a big muddy wall of noise were some delay based trickery not used.

We use other delay based effects in pro audio too. You've probably heard of a Phaser ( 0.1ms Delay) Flanger (5-15 ms Delay) and Chorus (20ms delay)

These are seriously microscopic times, but each effect is very distinctive. A Phaser is basically a 10,000th of a second delay and is of course very noticeable, so I'm guessing 1/40,000th of a second also would be very noticeable too, I wonder if the human ear is much more responsive than we are giving it credit for in this calculation?
Hi,
If you examine the telegraphers equations, then resistance does have an effect, but for this example, it is irrelevant.

Here is a link which indicates that the smallest inter-aural time difference the ear/brain can detect is 10us.

For speaker runs of a ten metres or less, it is not a problem. To achieve 10us delay in a cable, then the cable needs to be 2.4km long. Therefore, as long as the difference in length is no more than 2.4km, you will not hear any problems.

Regards,
Shadders.
 
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Longchops

Well-known member
Oct 15, 2020
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Hi,
If you examine the telegraphers equations, then resistance does have an effect, but for this example, it is irrelevant.

Here is a link which indicates that the smallest inter-aural time difference the ear/brain can detect is 10us.

For speaker runs of a ten metres or less, it is not a problem. To achieve 10us delay in a cable, then the cable needs to be 2.4km long. Therefore, as long as the difference in length is no more than 2.4km, you will not hear any problems.

Regards,
Shadders.

Amazing post! Incredible how they did that. I think that's the definitive answer.....

I would be very disappointed in myself if I couldn't achieve the 6.9us response that the 'trained listeners' got though. So I guess I could nit pick that down to 1.6km :LOL:

Completely impossible for hifi, but definitely possible for outdoor events or arenas

You still wouldn't catch me using wildly different cable lengths though. Its just wrong :LOL:
 

abacus

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Sep 24, 2008
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There are different types of enhancer, which type are you talking about? If the typical pedal switch that is part of the effect pedals used by guitarists, then it is just an effect, not a corrector.

If you are talking an aural enhancer then this is to bring out the best bits of the guitar by cleaning up the bass and generally altering the frequency response for best sound. (Could be called a corrector as it cleans up guitar problems, but has nothing to do with cables)

Bill
 

Longchops

Well-known member
Oct 15, 2020
59
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45
There are different types of enhancer, which type are you talking about? If the typical pedal switch that is part of the effect pedals used by guitarists, then it is just an effect, not a corrector.

If you are talking an aural enhancer then this is to bring out the best bits of the guitar by cleaning up the bass and generally altering the frequency response for best sound. (Could be called a corrector as it cleans up guitar problems, but has nothing to do with cables)

Bill

Its not quite that cut and dry, sometimes both types can be the same. It depends who makes it as to what it does and how it works. I'm talking about the enhancers that use phase shifting to slow certain frequencies (ie a micro delay) which I believe is the type of enhancement you will find in guitar pedals; the only reason I brought it up and considered it relevant was because I was questioning the maths behind what the shortest perceptible delay time was.

A lot of aural enhancers/exciters/psychoacoustic randomisers/etc are just glorified EQs. To be honest I've never really found a use for them.

We could argue all day whether EQ or Enhancers are effects, correctional devices or both so I'd quickly draw a line under that one and have to agree to disagree with you. I do agree that this is well and truly off topic now though, haha.

Cheers
 

Paul Clarke

Well-known member
Oct 12, 2007
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This thread is excellent timing, as I'm considering a cable upgrade myself.
Due to room layout, I really have no option than to have different lengths. I currently have 1.5m and 3.5m. It's been like this for years. Maybe there is a difference, but it will have inevitably become part of my "sound". My next purchase will probably be 2m and 4m, so a 50% difference. I accept the laws of electricity that a longer distance will ultimately increase the overall resistance and I also accept that one channel of my amp will presumably be working harder to overcome that additional resistance. (Surely we're considering huge runs of many thousands of metres in practice?)
However, whilst I understand the laws apply, in real terms how much difference could this possibly make over such relatively short distances? My dealer (who I trust) has urged caution, which I respect, but whilst a difference may apply in theory and may be picked up on measuring equipment, in practice is there any way this could be picked up by the ear? It is completely impractical and certainly not cost effective to coil up 2 metres of cable somehow (which also causes resistance), just to get the balance.
I'm intrigued by this and interested in the thoughts of learned board members!
 

Gray

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Nov 27, 2015
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This thread is excellent timing, as I'm considering a cable upgrade myself.
Due to room layout, I really have no option than to have different lengths. I currently have 1.5m and 3.5m. It's been like this for years. Maybe there is a difference, but it will have inevitably become part of my "sound". My next purchase will probably be 2m and 4m, so a 50% difference. I accept the laws of electricity that a longer distance will ultimately increase the overall resistance and I also accept that one channel of my amp will presumably be working harder to overcome that additional resistance. (Surely we're considering huge runs of many thousands of metres in practice?)
However, whilst I understand the laws apply, in real terms how much difference could this possibly make over such relatively short distances? My dealer (who I trust) has urged caution, which I respect, but whilst a difference may apply in theory and may be picked up on measuring equipment, in practice is there any way this could be picked up by the ear? It is completely impractical and certainly not cost effective to coil up 2 metres of cable somehow (which also causes resistance), just to get the balance.
I'm intrigued by this and interested in the thoughts of learned board members!
If you didn't know about the difference in length Paul, you wouldn't hear it.
 

shadders

Well-known member
Nov 19, 2009
152
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18,670
This thread is excellent timing, as I'm considering a cable upgrade myself.
Due to room layout, I really have no option than to have different lengths. I currently have 1.5m and 3.5m. It's been like this for years. Maybe there is a difference, but it will have inevitably become part of my "sound". My next purchase will probably be 2m and 4m, so a 50% difference. I accept the laws of electricity that a longer distance will ultimately increase the overall resistance and I also accept that one channel of my amp will presumably be working harder to overcome that additional resistance. (Surely we're considering huge runs of many thousands of metres in practice?)
However, whilst I understand the laws apply, in real terms how much difference could this possibly make over such relatively short distances? My dealer (who I trust) has urged caution, which I respect, but whilst a difference may apply in theory and may be picked up on measuring equipment, in practice is there any way this could be picked up by the ear? It is completely impractical and certainly not cost effective to coil up 2 metres of cable somehow (which also causes resistance), just to get the balance.
I'm intrigued by this and interested in the thoughts of learned board members!
Hi,
The distances you refer to will make no difference. The problem is that people think about this, and then believe it does make a difference and worry about it.

So, purchase the cable the same lengths and use a figure of 8 to take up the slack in the shorter requirement path, or snake the cable. Coiling will increase the inductance, but again, people may know this and start worrying about it.

If the cables cost a lot of money, such as £00's or £000's per metre, then this may be the reaon the dealer is reluctant to sell shorter lengths.

Regards,
Shadders.
 
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Longchops

Well-known member
Oct 15, 2020
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This thread is excellent timing, as I'm considering a cable upgrade myself.
Due to room layout, I really have no option than to have different lengths. I currently have 1.5m and 3.5m. It's been like this for years. Maybe there is a difference, but it will have inevitably become part of my "sound". My next purchase will probably be 2m and 4m, so a 50% difference. I accept the laws of electricity that a longer distance will ultimately increase the overall resistance and I also accept that one channel of my amp will presumably be working harder to overcome that additional resistance. (Surely we're considering huge runs of many thousands of metres in practice?)
However, whilst I understand the laws apply, in real terms how much difference could this possibly make over such relatively short distances? My dealer (who I trust) has urged caution, which I respect, but whilst a difference may apply in theory and may be picked up on measuring equipment, in practice is there any way this could be picked up by the ear? It is completely impractical and certainly not cost effective to coil up 2 metres of cable somehow (which also causes resistance), just to get the balance.
I'm intrigued by this and interested in the thoughts of learned board members!

If it takes 2.4km of cable to make a 10us delay time

then a 2.4 metre difference would be 0.001us of delay

I was completely satisfied with this. But now you've brought into question the resistance of the cable and the fact the amp would have to work fractionally harder to overcome this, or the cable could absorb some of the signal. That could make the sound a bit lopsided

This guy agrees and recommends wires are as short as possible and the same size:

He says when the resistance of the cable reaches 5% of the speaker impedance then the effects become noticeable:

Found this table on wikipedia detailing maximum speaker wire lengths. If I'm understanding this correctly, then 22AWG wire could present a problem at that distance?

Maximum wire lengths for two conductor copper wire[4]
Wire size2 Ω load4 Ω load6 Ω load8 Ω load
22 AWG (0.326 mm2)3 ft (0.9 m)6 ft (1.8 m)9 ft (2.7 m)12 ft (3.6 m)
20 AWG (0.518 mm2)5 ft (1.5 m)10 ft (3 m)15 ft (4.5 m)20 ft (6 m)
18 AWG (0.823 mm2)8 ft (2.4 m)16 ft (4.9 m)24 ft (7.3 m)32 ft (9.7 m)
16 AWG (1.31 mm2)12 ft (3.6 m)24 ft (7.3 m)36 ft (11 m)48 ft (15 m)
14 AWG (2.08 mm2)20 ft (6.1 m)40 ft (12 m)60 ft (18 m)*80 ft (24 m)*
12 AWG (3.31 mm2)30 ft (9.1 m)60 ft (18 m)*90 ft (27 m)*120 ft (36 m)*
10 AWG (5.26 mm2)50 ft (15 m)100 ft (30 m)*150 ft (46 m)*200 ft (61 m)*
 

Paul Clarke

Well-known member
Oct 12, 2007
83
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18,545
If it takes 2.4km of cable to make a 10us delay time

then a 2.4 metre difference would be 0.001us of delay

I was completely satisfied with this. But now you've brought into question the resistance of the cable and the fact the amp would have to work fractionally harder to overcome this, or the cable could absorb some of the signal. That could make the sound a bit lopsided

This guy agrees and recommends wires are as short as possible and the same size:

He says when the resistance of the cable reaches 5% of the speaker impedance then the effects become noticeable:

Found this table on wikipedia detailing maximum speaker wire lengths. If I'm understanding this correctly, then 22AWG wire could present a problem at that distance?

Maximum wire lengths for two conductor copper wire[4]
Wire size2 Ω load4 Ω load6 Ω load8 Ω load
22 AWG (0.326 mm2)3 ft (0.9 m)6 ft (1.8 m)9 ft (2.7 m)12 ft (3.6 m)
20 AWG (0.518 mm2)5 ft (1.5 m)10 ft (3 m)15 ft (4.5 m)20 ft (6 m)
18 AWG (0.823 mm2)8 ft (2.4 m)16 ft (4.9 m)24 ft (7.3 m)32 ft (9.7 m)
16 AWG (1.31 mm2)12 ft (3.6 m)24 ft (7.3 m)36 ft (11 m)48 ft (15 m)
14 AWG (2.08 mm2)20 ft (6.1 m)40 ft (12 m)60 ft (18 m)*80 ft (24 m)*
12 AWG (3.31 mm2)30 ft (9.1 m)60 ft (18 m)*90 ft (27 m)*120 ft (36 m)*
10 AWG (5.26 mm2)50 ft (15 m)100 ft (30 m)*150 ft (46 m)*200 ft (61 m)*
Jeez!

Why does hifi have to be so complicated sometimes?!? 🙄
I don't even understand that table! 😆
Interesting article though. (y)
 
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Longchops

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Oct 15, 2020
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Jeez!

Why does hifi have to be so complicated sometimes?!? 🙄
I don't even understand that table! 😆
Interesting article though. (y)
I think I may be overcomplicating this somewhat, haha :LOL:

I'm probably quite close to 22AWG in my own setup tbh, as my speaker cables are line level so is just a bog standard RCA cable, might actually spend a fiver and get a better one after reading that!
 
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shadders

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Nov 19, 2009
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I think I may be overcomplicating this somewhat, haha :LOL:

I'm probably quite close to 22AWG in my own setup tbh, as my speaker cables are line level so is just a bog standard RCA cable, might actually spend a fiver and get a better one after reading that!
Hi,
QED79 strand is 14AWG (2.5mm^2), so it is unlikely any speaker cable purchased from a hifi dealer will be this cross sectional area at least.

Regards,
Shadders.
 
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Gray

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:) The bloke doesn't appear to realise the real reason why Naim specify a minimum 3.5 metre length (of their own cable).
The topic has been mentioned a few times on the forum.
The first 3 lines of this explains:
 
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nopiano

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Feb 15, 2009
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The difference in resistance between a typical 2 metre cable and a 4 metre one might well be less than the difference in resistance between two mass produced speakers comprising a pair. It’s a non issue as far as the amplifier is concerned.

But I’d buy a matching pair and loop one side back on itself as already suggested.
 
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Matte

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Sep 22, 2014
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The wavelength (360 deg.) at 20kHz in air is approx 15km. So even if you were to add the the possible effect of the insulation and the reduced ‘speed’ through copper at 0.8 velocity factor, it’s still 12km. So out of phase (180 deg.) is 6km.
Restive difference is dependent more on cross sectional area. There are other factors but effect are just as minimal.
So cable lengths make absolutely no difference. This has been said but I thought I’d reinforce the opinion. And that’s at 20kHz who hears that?
 
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