Author Topic: The 'Skin Effect' for speaker wire.  (Read 4365 times)

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Offline BrianHG

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Re: The 'Skin Effect' for speaker wire.
« Reply #25 on: January 09, 2019, 08:05:41 am »
Especially compared to the chinese wires those develop green copper oxide just by sitting on the shelf, rendering them unsolderable...
Yes, avoiding crap wire is also important.  With such corrosion, your sound will be affected over time as the cable's lowers in impedance and crackles due to copper filaments flaking away.
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Offline Bassman59

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Re: The 'Skin Effect' for speaker wire.
« Reply #26 on: January 09, 2019, 10:34:30 am »
Yes, avoiding crap wire is also important.  With such corrosion, your sound will be affected over time as the cable's lowers in impedance and crackles due to copper filaments flaking away.

The corrosion will increase the wire resistance, which is bad, of course.
 

Offline boB

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Re: The 'Skin Effect' for speaker wire.
« Reply #27 on: January 09, 2019, 11:52:40 am »

I only use powered studio monitors.  No speaker cables to choose from. 

The cable that IS in there is very short so problem solved !

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Online dzseki

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Re: The 'Skin Effect' for speaker wire.
« Reply #28 on: January 09, 2019, 06:19:25 pm »

I only use powered studio monitors.  No speaker cables to choose from. 

The cable that IS in there is very short so problem solved !

Solved? Shifted! You have a long, highly capacitive coaxial cable that is not terminated on its characteristic impedance instead  :-DD
 

Offline Gr8fulFox

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Re: The 'Skin Effect' for speaker wire.
« Reply #29 on: January 10, 2019, 10:11:07 pm »

I only use powered studio monitors.

Bah; too small. Bigger is always better. ;D

And yes, in that photo, we're using 12-gauge extension cord that we pulled out of a dumpster. But that thickness is pointless because I had to trim it down so it would fit in the banana plugs.
« Last Edit: January 12, 2019, 01:25:41 am by Gr8fulFox »
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Offline boB

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Re: The 'Skin Effect' for speaker wire.
« Reply #30 on: January 11, 2019, 04:41:13 pm »

I only use powered studio monitors.

Bah; too small. Bigger is always better. ;D

And yes, in that photo, we're using 12-guage extension cord that we pulled out of a dumpster. But that thickness is pointless because I had to trim it down so it would fit in the banana plugs.

Ewwwww  !  Cerwin Vegas !

Those were neat old speakers.
K7IQ
 
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Offline Gr8fulFox

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Re: The 'Skin Effect' for speaker wire.
« Reply #31 on: January 16, 2019, 01:03:05 am »

I only use powered studio monitors.

Bah; too small. Bigger is always better. ;D

And yes, in that photo, we're using 12-guage extension cord that we pulled out of a dumpster. But that thickness is pointless because I had to trim it down so it would fit in the banana plugs.

Ewwwww  !  Cerwin Vegas !

Those were neat old speakers.

Cerwin-Vega is the BEST!


I'm a former cigarette smoker, but I love my Zippo 'windproof' lighter; that being said, when I crank-up "Baby Got Back" on the 'Bleeder, the air pressure from the woofers is enough to snuff-out my Zippo; "WINDPROOF", MY ASS!!
« Last Edit: January 16, 2019, 01:11:38 am by Gr8fulFox »
If you get confused, JUST LISTEN TO THE MUSIC PLAY!

h++ps://www.youtube.com/watch?v=XVbvvoNYTpw
 

Offline nctnico

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Re: The 'Skin Effect' for speaker wire.
« Reply #32 on: January 16, 2019, 01:39:17 am »
I would not bother about skin effect. Only tiny part of total power is at high frequencies, and max frequency is not that high anyway. Thus effect is negligent.
Understood, however, this is an exercise in a real effect which actually exists and can be measured and what in theory is the best type of wiring for a speaker given that all 3 wires are identically priced.
Measured how? In theory the wire with the individually isolated strands will have the lowest AC resistance. In many transformers for higher power DC-DC converters skin effect is a problem as well.
There are small lies, big lies and then there is what is on the screen of your oscilloscope.
 

Offline boB

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Re: The 'Skin Effect' for speaker wire.
« Reply #33 on: January 16, 2019, 04:50:17 am »
Skin effect in speaker wires is bullshit.  I defy anyone to be able to tell the difference using some kind of AB/X test other than 50% guessing which cable they are listening to  (for a normal cable run length)

Even at higher frequencies, where skin effect is more prominent, there is less power used in those frequencies and resistance at high audio frequencies is less important.

If you want to reduce skin effect, buy some $3000+ Litz wire speaker cables that are readily available from companies that are all to excited to separate you from your money.

« Last Edit: January 16, 2019, 04:54:50 am by boB »
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Offline BrianHG

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Re: The 'Skin Effect' for speaker wire.
« Reply #34 on: January 17, 2019, 06:15:30 am »
Ewwwww  !  Cerwin Vegas !

Those were neat old speakers.

Cerwin-Vega is the BEST!
:-+ Ewwwww  !  Cerwin Vegas !  :-DD
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Offline Red Squirrel

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Re: The 'Skin Effect' for speaker wire.
« Reply #35 on: January 17, 2019, 06:45:52 am »
I think skin effect is also a bigger issue with high currents and speakers are decently low current so probably not worth accounting for.   Suppose in a huge auditorium situation with many very high powered speakers like 1,000w+ maybe you'd use litz wire, but even then not sure if that's done or not.
 

Online wraper

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Re: The 'Skin Effect' for speaker wire.
« Reply #36 on: January 17, 2019, 06:52:33 am »
I think skin effect is also a bigger issue with high currents and speakers are decently low current so probably not worth accounting for.   Suppose in a huge auditorium situation with many very high powered speakers like 1,000w+ maybe you'd use litz wire, but even then not sure if that's done or not.
Of course it's not used. Skin is very thick at audio frequencies. And you would even increase resistance (for the same wire outer diameter) at lower frequencies where most of the power is due to lower conductor density. Not to say litz wire is a pain to terminate.
 
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Offline Red Squirrel

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Re: The 'Skin Effect' for speaker wire.
« Reply #37 on: January 17, 2019, 07:13:17 am »
I think skin effect is also a bigger issue with high currents and speakers are decently low current so probably not worth accounting for.   Suppose in a huge auditorium situation with many very high powered speakers like 1,000w+ maybe you'd use litz wire, but even then not sure if that's done or not.
Of course it's not used. Skin is very thick at audio frequencies. And you would even increase resistance (for the same wire outer diameter) at lower frequencies where most of the power is due to lower conductor density. Not to say litz wire is a pain to terminate.

Yeah kinda figured, not worth the extra cost either.  Any differences it would even have would probably be outside of the hearing range too.   
 

Offline raptor1956

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Re: The 'Skin Effect' for speaker wire.
« Reply #38 on: January 17, 2019, 07:49:34 am »
We used Litz wire to power the vehicles in the AMHS (Automated Material Handling System) used in the semiconductor industry to transport FOUPS with wafers around the FAB.  These wires were run as a loop inside the track and the vehicles had "cores" to pickup the power from the Litz wire.  Essentially the core is the secondary of a transformer and the two parallel Litz wires serve as the primary.  But, because there are only two wires and cores are limited to about 15cm in length you need to do something to improve the power transfer as 50Hz or 60Hz just won't do.  So, the power supply, sometimes called an SCPS (Super Clean Power Supply), would provide about 300V AC power at about 9KHz and around 8A.  By boosting the frequency to 9KHz the lines cut quicker through the core permitting greater power transfer and greater efficiency.  Each loop could power about 14 vehicles each weighing about 100kg or more.  So, in this application, we used Litz wire because of the higher frequency (9KHz).

Once installed the adjustment/tuning involved adjusting the inductance and capacitance within the SCPS to achieve the most efficient power circuit possible.  It could take a few minutes to several hours to get the line balanced properly.  The engineers would attempt to use LCR meters to calculate what the appropriate inductance and capacitance should be, but the skilled techs could tune it 10X faster using trial and error.  Funny how that works sometimes. 


Brian
« Last Edit: January 17, 2019, 09:48:36 am by raptor1956 »
 
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Offline Bassman59

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Re: The 'Skin Effect' for speaker wire.
« Reply #39 on: January 17, 2019, 09:41:43 am »
I think skin effect is also a bigger issue with high currents and speakers are decently low current so probably not worth accounting for.   Suppose in a huge auditorium situation with many very high powered speakers like 1,000w+ maybe you'd use litz wire, but even then not sure if that's done or not.
No way. Back when amplifiers were in side-stage racks and separate from speaker cabinets, we used standard SOJ-type mains-power cordage, 12 AWG or thicker, for speaker cable runs. That cable is flexible, strong and has insulation good enough so that it could sit in puddles and not affect the system. Thick stranded cable was important for subwoofers, where you need low I2R losses so your amp damping factor didn't go to hell and also so the power went to the drivers and not to heat in the cable. And remember that the frequency response of subs doesn't go up past 80 Hz or so, so do the math and work out skin depth for that frequency.

Now, of course, the amplifiers are built into the speaker cabinets, as they should be.
 
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Offline raptor1956

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Re: The 'Skin Effect' for speaker wire.
« Reply #40 on: January 17, 2019, 09:55:52 am »
I think skin effect is also a bigger issue with high currents and speakers are decently low current so probably not worth accounting for.   Suppose in a huge auditorium situation with many very high powered speakers like 1,000w+ maybe you'd use litz wire, but even then not sure if that's done or not.
No way. Back when amplifiers were in side-stage racks and separate from speaker cabinets, we used standard SOJ-type mains-power cordage, 12 AWG or thicker, for speaker cable runs. That cable is flexible, strong and has insulation good enough so that it could sit in puddles and not affect the system. Thick stranded cable was important for subwoofers, where you need low I2R losses so your amp damping factor didn't go to hell and also so the power went to the drivers and not to heat in the cable. And remember that the frequency response of subs doesn't go up past 80 Hz or so, so do the math and work out skin depth for that frequency.

Now, of course, the amplifiers are built into the speaker cabinets, as they should be.


Most speakers are still powered by external amps with the exception of bass/woofers that have long used internal amps.  I do think that going forward it makes a lot of sense to include the proper matched amps inside all speakers and then the signal can be sent wirelessly or via a lan cable.  All equalization and cross-over work should be done within the speaker digitally and then the output sent to the amps for each of the driver circuits -- in a 3-way speaker there would then be 3 amps exactly matched to the driver(s) it drives.  In addition to the digital audio signal sent to the speakers there should also be timing information to account for speaker placement and associated delays.  A receiver in such a system would have no amplification function but instead would serve as a source switch and a controlling element that tells each speaker what there power output should be and there respective delay.


Brian
 
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Offline helius

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Re: The 'Skin Effect' for speaker wire.
« Reply #41 on: January 17, 2019, 12:08:55 pm »
When you say "delay" are you speaking of electrical delay or acoustic delay?
In any reasonable size room electrical delay is insignificant.
Acoustic delay is an intended part of stereo reproduction. The sound reaching the ears at different times is what causes it to localize in space. The distinction between phase and group delay is also very important for stereo.
 

Offline cdev

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Re: The 'Skin Effect' for speaker wire.
« Reply #42 on: January 17, 2019, 12:34:07 pm »
Having an active speaker especially with some feedback mechanism to cancel out distortion works great, but I wouldn't personally want one to use a LAN for multichannel audio because of latency issues, unless it has some synchronous protocol. (Likely some do, I am just not familiar with them!)

Basically, digital audio would likely be fine with any format meant for it.

But a LAN protocol to replace multiple speaker lines doesn't seem like a good choice, unless all channels are sent together, reason being, some protocols have overhead while they wait until enough data needs to be sent, if that delay was asymmetrical, not good.. channels might get out of sync unless the delay was short enough to not be perceptible. The same issues likely apply to wireless (LAN?) (Bluetooth) Fine if they are all sent and received together, likely would break if stereo pairs in particular were sent separately because the latency might well be different. I would not be surprised if the effect was an echo or similar.


Most speakers are still powered by external amps with the exception of bass/woofers that have long used internal amps.  I do think that going forward it makes a lot of sense to include the proper matched amps inside all speakers and then the signal can be sent wirelessly or via a lan cable.  All equalization and cross-over work should be done within the speaker digitally and then the output sent to the amps for each of the driver circuits -- in a 3-way speaker there would then be 3 amps exactly matched to the driver(s) it drives.  In addition to the digital audio signal sent to the speakers there should also be timing information to account for speaker placement and associated delays.  A receiver in such a system would have no amplification function but instead would serve as a source switch and a controlling element that tells each speaker what there power output should be and there respective delay.


Brian
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Offline ajb

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Re: The 'Skin Effect' for speaker wire.
« Reply #43 on: January 18, 2019, 02:50:15 am »
Big stage shows use line arrays, usually just one set to each side of the stage, but occasionally you see a set of delay towers as well if the venue is deep enough.  You don't need complicated controllers built into every cabinet to deal with that effectively.  Delays and EQs can be set in the console, which is all digital.  Anyway modern amps can fit 10kW of amplification plus DSP plus network control into 2RU, and it just doesn't make sense to spread 6RU of equipment out into 16 cabinets of a reasonably sized array.  Plus you'd have to run power+signal to every single cabinet, and you'd have three times as many devices to manage and configure, and once the array is hoisted you can't get to the cabinets, so what would you do if one of the fancy in-cab controllers goes insane ten minutes before doors? 

And yes, audio over IP is already standard.  Massive multi-channel snakes with dozens of copper lines are gone, you plug your mixing console into the show network, and it talks DANTE to your stage boxes through a fiber backbone.  A Cisco cert is a legitimately marketable qualification for the modern stagehand (although now there are several lines of networking infrastructure gear purpose-built for production usage, so standard enterprise networking gear is becoming less common).
 
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Offline free_electron

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Re: The 'Skin Effect' for speaker wire.
« Reply #44 on: January 18, 2019, 06:14:26 am »
as current goes up the depth decreases. electrons run at the surface. so a broad flat wire is better as there is more 'surface'. a broad copper foil would work best.

bob pease did the experiment once. he grabbed two sections of 40 wire ribbon cable. worked liek a champ !
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Offline BrianHG

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Re: The 'Skin Effect' for speaker wire.
« Reply #45 on: January 18, 2019, 06:43:17 am »
as current goes up the depth decreases. electrons run at the surface. so a broad flat wire is better as there is more 'surface'. a broad copper foil would work best.

bob pease did the experiment once. he grabbed two sections of 40 wire ribbon cable. worked liek a champ !
Thanks for the search idea:
Google Images of flat+speaker+wire
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Online dzseki

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Re: The 'Skin Effect' for speaker wire.
« Reply #46 on: January 18, 2019, 07:28:33 am »
Although this will yield a highly capacitive cable that may cause trouble for certain amplifiers.
as current goes up the depth decreases. electrons run at the surface. so a broad flat wire is better as there is more 'surface'. a broad copper foil would work best.

bob pease did the experiment once. he grabbed two sections of 40 wire ribbon cable. worked liek a champ !
 

Offline free_electron

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Re: The 'Skin Effect' for speaker wire.
« Reply #47 on: January 18, 2019, 07:57:45 am »
Although this will yield a highly capacitive cable that may cause trouble for certain amplifiers.
as current goes up the depth decreases. electrons run at the surface. so a broad flat wire is better as there is more 'surface'. a broad copper foil would work best.

bob pease did the experiment once. he grabbed two sections of 40 wire ribbon cable. worked liek a champ !

he used one 40 wire ribbon for the + , one 40 wire ribbon for the -

and even then. that bit of pf for a high power amp is peanuts. there's more capacitance in the crossover network than in the cable...
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Offline raptor1956

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Re: The 'Skin Effect' for speaker wire.
« Reply #48 on: January 18, 2019, 10:07:30 am »
Having an active speaker especially with some feedback mechanism to cancel out distortion works great, but I wouldn't personally want one to use a LAN for multichannel audio because of latency issues, unless it has some synchronous protocol. (Likely some do, I am just not familiar with them!)

Basically, digital audio would likely be fine with any format meant for it.

But a LAN protocol to replace multiple speaker lines doesn't seem like a good choice, unless all channels are sent together, reason being, some protocols have overhead while they wait until enough data needs to be sent, if that delay was asymmetrical, not good.. channels might get out of sync unless the delay was short enough to not be perceptible. The same issues likely apply to wireless (LAN?) (Bluetooth) Fine if they are all sent and received together, likely would break if stereo pairs in particular were sent separately because the latency might well be different. I would not be surprised if the effect was an echo or similar.


Most speakers are still powered by external amps with the exception of bass/woofers that have long used internal amps.  I do think that going forward it makes a lot of sense to include the proper matched amps inside all speakers and then the signal can be sent wirelessly or via a lan cable.  All equalization and cross-over work should be done within the speaker digitally and then the output sent to the amps for each of the driver circuits -- in a 3-way speaker there would then be 3 amps exactly matched to the driver(s) it drives.  In addition to the digital audio signal sent to the speakers there should also be timing information to account for speaker placement and associated delays.  A receiver in such a system would have no amplification function but instead would serve as a source switch and a controlling element that tells each speaker what there power output should be and there respective delay.


Brian

Maybe not the right term, by LAN I really meant digital audio.  OTH, with a clock signal for synchronization you can get around latency.


Brian
 

Offline LapTop006

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Re: The 'Skin Effect' for speaker wire.
« Reply #49 on: January 18, 2019, 09:59:09 pm »
... A Cisco cert is a legitimately marketable qualification for the modern stagehand (although now there are several lines of networking infrastructure gear purpose-built for production usage, so standard enterprise networking gear is becoming less common).

Which of course really just means that connectors aside (Neutrik FibreConn & EtherConn are wonderful) they're largely terrible crap, luckily given the trivial data rates involved that's not a problem.
 


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