Technical Article: Does Audio Cable Skin Effect Matter

[GeorgeBynum]

Turns out buying 18 gauge insulated copper wires and twisting 2 together to make one 16 gauge speaker wire is even the cheapest deal I have found ...

I hate to burst your bubble, but 2 18AWG in parallel would be 15 AWG. Yes, wire sizes other than even numbers exist; indeed, many years ago, my then employer used 25.5 AWG for winding some coils.

 

[Speedskater]

Unless an AWG wire is safety listed for AC power, it may not actually the AWG size that's printed on the label.

 

[threni]

I seem to remember an Ivorbiggen.

You bloody well should!

 

[Katji]

Great. Just great. But still, a relatively good choice out of new posts in RSS. Just minor glitch, dubious reasoning re the youtube reviewer.

 

[mhardy6647]

enstupidation.

I am adopting this word as of this morning!
I shall endeavor to use it daily -- which, nowadays, should be a distressingly easy challenge to meet.

 

[kongwee]

Definitely no flat cable for me.

 

[mhardy6647]

LOL, every single word in the dictionary started out as made up sounds

First-hand evidence:

skip to 1:42

 

[Audiofire]

Stupefaction seems to work in the hi-fi industry. What do you think about this quote? Are phase shifts of skin effect also FUD in relation to audio cables?

"Skin-effect occurs when the high-frequency currents flow on the outer "skin" of the conductors whereas lower frequencies have more uniform current distribution across the conductor cross-section. This happens when too large a gauge is chosen for the conductors. The effect is that the impedance (primarily inductance and capacitance) is different for low frequencies than high frequencies. This difference in impedance can cause phase shifts in high-frequency passages relative to low-frequency passages, causing a smearing effect to the music. If a sufficiently small gauge is chosen for the conductors, all frequencies are "forced" to flow more uniformly in the conductors. Empirical Audio minimizes skin effect by careful choice of conductor size to optimize for low as well as high frequencies. This insures that the current distribution is relatively uniform at all audio frequencies."

What makes an excellent Speaker Cable? : Empirical Audio

Manufacturer of high-end audio components, specializing in Computer Audio and providing personalized service. Direct sales from USA.

www.empiricalaudio.com

 

[mhardy6647]

Definitely no flat cable for me.

 

[Katji]

^^Edge profiled over time by the water and sand pouring over the edge.

...hey, no wonder there's a water shortage.

 

[mhardy6647]

Lifestyle cables.

... which, I have to admit, sounds like something that might be found someplace in 50 Shades of Gray.

(source: https://www.audiosciencereview.com/...cables-do-you-use-in-your-systems.5398/page-9 )

 

[Katji]

^^^ Shock and horror.

 

[dc655321]

Are phase shifts of skin effect also FUD in relation to audio cables?

Yes.
Non-exotic cables are basically a (v. small) resistor at audio frequencies.

 

[Audiofire]

It seems to me that the reason why some amplifiers could self-oscillate from litz-type speaker wire is because of parasitic capacitance or parasitic inductance, induced from having those smaller wires in close proximity.

It could be that some power cables are used as speaker cables. That could also be the cheapest solution and would work fine if the conductors are spaced apart for most of the length, and the total gauge provides the right resistance from what I can see.

So that's why I pointed out that coupling multiple smaller gauges together could be the cheapest option and a way to deal with skin effect at the same time, which is also a nice way to actually use the copper that was paid for.

 

[SIY]

It seems to me that the reason why some amplifiers could self-oscillate from litz-type speaker wire is because of parasitic capacitance or parasitic inductance, induced from having those smaller wires in close proximity.

It could be that some power cables are used as speaker cables. That could also be the cheapest solution and would work fine if the conductors are spaced apart for most of the length, and the total gauge provides the right resistance from what I can see.

So that's why I pointed out that coupling multiple smaller gauges together could be the cheapest option and a way to deal with skin effect at the same time, which is also a nice way to actually use the copper that was paid for.

Or... you can understand that there's no "issue" that you need to "deal with."

 

[Audiofire]

Or... you can understand that there's no "issue" that you need to "deal with."

It was stated earlier in the thread that some amplifiers are known to self-oscillate from litz wire, so not sure whether it is appropriate to write the discussion off.

Speaker wire can oxidize in some situations, so it's important to seal the conductor off from the air with insulation tape or another method. Skin effect could be a problem with oxidized speaker wire. So maybe, people heard an audible improvement from litz wire on speakers after all.

PVC can leak hydrochloric acid, chlorinated hydrocarbons and plasticizers as well:

Aw geez my speaker wire has turned green inside the jacket.

Ok, so 6-8 years ago I bought a spool of 12 gauge wire at a box store not to mention any name, but the orange one. What can I say, it was on clearance? It's a shame, as I have the whole theatre room wired up with this (now green) crap. Interestingly enough, it seems worst inside the jacket...

audiokarma.org

What do you think?

 

[Katji]

Speaker wire can oxidize in some situations, so it's important to seal the conductor off from the air with insulation tape or another method. Skin effect could be a problem with oxidized speaker wire. So maybe, people heard an audible improvement from litz wire on speakers after all.

PVC can leak hydrochloric acid, chlorinated hydrocarbons and plasticizers as well:

That's why many people use power/mains cable instead of the typical/basic [twinflex] speaker wire...apparently it does not oxidise like that, and/or they prefer the appearance of it.

 

[SIY]

It was stated earlier in the thread that some amplifiers are known to self-oscillate from litz wire, so not sure whether it is appropriate to write the discussion off.

Speaker wire can oxidize in some situations, so it's important to seal the conductor off from the air with insulation tape or another method. Skin effect could be a problem with oxidized speaker wire. So maybe, people heard an audible improvement from litz wire on speakers after all.

PVC can leak hydrochloric acid, chlorinated hydrocarbons and plasticizers as well:

Aw geez my speaker wire has turned green inside the jacket.

Ok, so 6-8 years ago I bought a spool of 12 gauge wire at a box store not to mention any name, but the orange one. What can I say, it was on clearance? It's a shame, as I have the whole theatre room wired up with this (now green) crap. Interestingly enough, it seems worst inside the jacket...

audiokarma.org

What do you think?

1. Since there's no actual advantage to using high capacitance cable like Litz, don't use it.
2. If your amp is marginally stable, you have a bad amp. Good amps abound, so why try to accommodate someone else's incompetence?
3. The corrosion of the copper surface makes very little electrical difference at audio frequencies, it's more of an esthetic issue. That said, it is mostly a phenomenon of transparent PVC. The speaker cables I made a decade ago with plain old black zip cord meant for outdoor lighting show no signs of an issue. Solution: don't use transparent PVC. Plain old #12 or #14 zip cord is functional and reliable, so why sweat using something more exotic?

 

[Audiofire]

1. Since there's no actual advantage to using high capacitance cable like Litz, don't use it.
2. If your amp is marginally stable, you have a bad amp. Good amps abound, so why try to accommodate someone else's incompetence?
3. The corrosion of the copper surface makes very little electrical difference at audio frequencies, it's more of an esthetic issue. That said, it is mostly a phenomenon of transparent PVC. The speaker cables I made a decade ago with plain old black zip cord meant for outdoor lighting show no signs of an issue. Solution: don't use transparent PVC. Plain old #12 or #14 zip cord is functional and reliable, so why sweat using something more exotic?

The cables made for outdoors are most likely rubber. I thought that capacitance is reduced by keeping distance between the conductors. Twisted litz wire that has individually insulated conductors could have parasitic capacitance issues because of this, but I'm certainly not a technical expert and like to be corrected by science.

What about normal PVC that is not transparent? Is that a non-issue? I have found these insulated copper wires that do not use PVC, and they are also cheaper than the 2.5 mm² version:

60.7185-21 STÄUBLI - Wire | FlexiPlast-E; 1x0.75mm2; stranded; Cu; black; 500V; 15A; 100m | TME - Electronic components

STÄUBLI 60.7185-21 | Wire; FlexiPlast-E; 1x0.75mm2; stranded; Cu; black; 500V; 15A; 100m - This product is available in Transfer Multisort Elektronik. Check out our wide range of products.

www.tme.eu

60.7185-22 STÄUBLI - Wire | FlexiPlast-E; 1x0.75mm2; stranded; Cu; red; 500V; 15A; 100m | TME - Electronic components

STÄUBLI 60.7185-22 | Wire; FlexiPlast-E; 1x0.75mm2; stranded; Cu; red; 500V; 15A; 100m - This product is available in Transfer Multisort Elektronik. Check out our wide range of products.

www.tme.eu

Another thing I don't understand is how important the relative permittivity of the insulation is for speaker wire. Given that the skin effect exists there at large gauges. Some will say that polyethylene insulation is better for audio cables due to relative permittivity.

 

[SIY]

The cables made for outdoors are most likely rubber. I thought that capacitance is reduced by keeping distance between the conductors. Twisted litz wire that has individually insulated conductors could have parasitic capacitance issues because of this, but I'm certainly not a technical expert and like to be corrected by science.

What about normal PVC that is not transparent? Is that a non-issue? I have found these insulated copper wires that do not use PVC, and they are also cheaper than the 2.5 mm² version:

60.7185-21 STÄUBLI - Wire | FlexiPlast-E; 1x0.75mm2; stranded; Cu; black; 500V; 15A; 100m | TME - Electronic components

STÄUBLI 60.7185-21 | Wire; FlexiPlast-E; 1x0.75mm2; stranded; Cu; black; 500V; 15A; 100m - This product is available in Transfer Multisort Elektronik. Check out our wide range of products.

www.tme.eu

60.7185-22 STÄUBLI - Wire | FlexiPlast-E; 1x0.75mm2; stranded; Cu; red; 500V; 15A; 100m | TME - Electronic components

STÄUBLI 60.7185-22 | Wire; FlexiPlast-E; 1x0.75mm2; stranded; Cu; red; 500V; 15A; 100m - This product is available in Transfer Multisort Elektronik. Check out our wide range of products.

www.tme.eu

Another thing I don't understand is how important the relative permittivity of the insulation is for speaker wire. Given that the skin effect exists there at large gauges. Some will say that polyethylene insulation is better for audio cables due to relative permittivity.

They are not rubber, they are vinyl. I posted a link to them somewhere recently, maybe this thread.

Not sure how often this needs to be repeated: for audio speaker wires of domestic length, the only thing that electrically matters is DCR. Zip cord of appropriate gauge is reliable and does everything needed.