[kiteki]

Originally Posted by nick_charles /img/forum/go_quote.gif
 
it is pretty easy to measure small diffferences in FR in cables [/]

 
FR is only a single aspect.  If you twist lead, tin, copper, rosemary and thyme together the electrical signal will be altered, however still retaining a flat FR.

 

[Chris J]

If you're going to apply transmission line theory at audio frequencies, then your load impedance must also be matched to the line impedance, otherwise, the whole exercise is rather pointless. What good is it to have say, a 100 ohm output impedance driving a 100 ohm line, only to have that line terminated with a 10k ohm load? Are you also modifying your equipment so that their input impedances match the line impedance?

And at what frequency are you determining the line's "characteristic impedance"? A cable won't start approaching it's mathematical "characteristic impedance" until you're pretty well out of the audio range. Below that, the cable's impedance continuously rises.


se

1. show the fellas a reference for the chart
2. a fine point here, but those exact values only work for a 75 ohm cable, move the lines on the chart up or down for other characteristic impedances
3. in the audio bandwidth, kinda hard to hit a moving target, aint't it?
4. For an interconnect.....a 100 ohm load?:rolleyes: better have a VERY large coupling capacitor.

 

[liamstrain]

Quote:

I see this thread has skillfully returned back to cables.  Ok, well the rest was fun while it lasted!
 

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CAT5e as a speaker cable.
 

 
source:  http://www.hydrogenaudio.org/forums/index.php?s=9a169021bbd958cd122c1385a8c5e9aa&showtopic=14082&st=0, http://www.hydrogenaudio.org/forums/index.php?showtopic=14732
 

Spoiler: commercial%20application%20in%20audio

 
"Use twisted pair wiring, such as you can find inside any CAT5 ethernet cable or similar."
 

 

 
Aha.

 
All this relates to gauge and RLC - not material or dialectric or cryo or any of the other gunk usually thrown around. Nobody doubts that you need an appropriate conductor gauge for those applications. We doubt that swapping to silver changes anything fundamentally over using copper with a similar RLC spec. 

 

[kiteki]

Even if silver or 7N copper sounds amazing you can't fit a fat cat through a skinny pipe.  The 3.5mm jack has to be silver / ofc too, then there is the soldering, and ideally even the IC chips.  I suppose the battery is less important.

 

[maverickronin]

Quote:

Even if silver or 7N copper sounds amazing you can't fit a fat cat through a skinny pipe.  The 3.5mm jack has to be silver / ofc too, then there is the soldering, and ideally even the IC chips.  I suppose the battery is less important.

 
Actually you can if the skinny section of pipe is short enough.
 
Haven't we had this discussion before?  Electrons aren't just tiny little spheres and you can't treat them as such.

 

[kiteki]

I suppose electronics are more like Sonic the Hedgehog rather than Garfield then ...
 

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Anyway, if someone wants to actually test speaker cables or receivers this looks suitable to me -
 
http://www.ebay.com/itm/8-Zone-Premium-Speaker-Distribution-Controller-System-With-Headphone-Output-/350516469305
 
(you connect 1 and 2 to the same speaker, then switch)
 

Have fun!

 

[anetode]

Like anetode was saying, he's decided on the simplicity and equality of cables, so he thinks looking too deep into the studies isn't necessary, the result is the same anyway, you implied that as well saying if you take the 10 positive reults to the side, they'll turn out to be chance in the end anyway.

Decided to catch up on the thread and ran across this gem. kiteki: no. Reading up on cables has allowed me to learn about concepts I was completely unfamiliar with, like skin effect, impedance coupling, etc. If anything I now regard the physics of cables as a complex topic calling for a variety of different designs to account for different implementations. And I have no idea where you got the whole "looking too deep into the studies isn't necessary" comment when I've already spent time on this thread trying to convince you to do the opposite. I'm actually surprised that I'm offended at how much you've missed the point, please don't pretend to paraphrase anything that I've said ever again.

 

[kiteki]

I think most of the studies I've looked at are flawed in some way, for example these often quoted statiscs http://home.provide.net/~djcarlst/abx_wire.htm are all completely made up, when you look at the real study they're referring to.
 
Yes the Pras and Gustavino study looks flawed too.
 
 

[/]
I have no idea where you got the whole "looking too deep into the studies isn't necessary" comment

 
Um, looking back at page 41...
 

Originally Posted by anetode /img/forum/go_quote.gif
 
the simplest conclusion rather than one which is correct by necessity. /
 
This analogy is meant to apply to your approach to considering studies. You're applying too much philosophy (waxing about attitudes and such), too many preconceptions, which mean that you are trying to come up with a solution that you can admire rather than just accept. Hence why I refer to your approach as pseudo-skepticism. /
 
why do you refer to your subsequent distrust as being prompted by "scientific reason" when it is nothing more than methodological snobbery (at best, or a deeper ideological prejudice at worst)? /
 

Your hunch runs contrary to the obvious conclusion. You've found that people who are familiar with cable DBT results refer to the evidence as voluminous and one-sided, but your personal bias leads you to offer the alternative hypothesis is that there really aren't that many such tests and that most of them are flawed. This is pseudoskepticism.

If you're wondering about all these countless tests, take my previous advice in this thread and go to a library and look them up in a database (otherwise, some links don't come cheap). There you will find properly designed and peer reviewed DBTs accompanied by thorough statistical analyses. Sticking to internet-only sources puts you at a disadvantage. Not only that, but it sometimes comes across like you're asking others to do all the research legwork for you and claiming that they're wrong if they don't.

 

The link you provided is an article from 1987, the preview goes into a lot of detail about the vinyl rig and electrostatic speakers, however it says nothing about the cables or number of listeners in the test, it did say they think ABAB versus AAAA could be more accurate than ABX though, which I definitely think could be true in some cases and I'd like to see a Foobar plug-in supporting that testing method, or similar same-different method.

Which is why my point was that you'd need more than a free online preview

 
etc...

 

[anetode]

 

[kiteki]

Yes, good luck with that.

 

[drez]

Not sure if anyone has posted this yet - but this is a very interesting article: http://en.goldenears.net/index.php?mid=KB_Columns&document_srl=1301
 
Basically with cables, the more I read, the more I realise how little I actually understand electronics.  Another interesting cable review with measurements: http://www.hometheaterhifi.com/volume_14_4/legenburg-zeus-cables-12-2007.html
 
I am starting to worry - I just bought $60 worth or rectangular OCC copper for a HE-6 recable (mostly because stock cable is oxidising) but I am starting to think I would have been better off using round wires in star quad, just keeping the gauge under 26 AWG (in order that the wire is less than 20 kHz skin depth - at least if I got my calcs correct).  Anyway I'm glad I didn't buy ROCC silver which would have cost me about 5 times more...
 
So star quad seems to be the geometry which most pro-audio companies use for their cables?  I can do this construction with my rectangular wire and just hope the capacitance isn't too high.
 
As far as I can get my head around it, phase and temporal distortion seems to be the main concerns in designing audio cables, but for the life of me I don't see how conductor metallurgy has anything to do with this, but then again I am not really an expert in any field which would cover this.  From my understanding, conductor purity/metallurgy has an influence over signal propagation speed, but I have no idea how this would affect critical performance metrics (in my understanding) such as phase distortion.
 
You would think that cable manufacturers, given how ready they are to publish scientific justifications for their cable products, would participate more in threads such as this.  Presumably, given their marketing material, they must employ at least a couple of engineers or scientists.  When people start wrongly representing other products, more often than not a rep from the company notices and chimes in to set things straight.  Maybe we just need to drop a few company names?

 

[Steve Eddy]

Quote:

Originally Posted by drez /img/forum/go_quote.gif
 
From my understanding, conductor purity/metallurgy has an influence over signal propagation speed, but I have no idea how this would affect critical performance metrics (in my understanding) such as phase distortion.
 
 

 
Not sure where you got that understanding from. Velocity of propagation depends on the permittivity of the medium the signal is propagating through. Since there's no electric field below the surface of a conductor, this means that it's dependent on the medium surrounding the conductor.
 
Cables are minimum phase, so they won't cause phase distortion.
 
se

 

[Chris J]

Quote:

Not sure if anyone has posted this yet - but this is a very interesting article: http://en.goldenears.net/index.php?mid=KB_Columns&document_srl=1301
 
Basically with cables, the more I read, the more I realise how little I actually understand electronics.  Another interesting cable review with measurements: http://www.hometheaterhifi.com/volume_14_4/legenburg-zeus-cables-12-2007.html
 
I am starting to worry - I just bought $60 worth or rectangular OCC copper for a HE-6 recable (mostly because stock cable is oxidising) but I am starting to think I would have been better off using round wires in star quad, just keeping the gauge under 26 AWG (in order that the wire is less than 20 kHz skin depth - at least if I got my calcs correct).  Anyway I'm glad I didn't buy ROCC silver which would have cost me about 5 times more...
 
So star quad seems to be the geometry which most pro-audio companies use for their cables?  I can do this construction with my rectangular wire and just hope the capacitance isn't too high.
 
As far as I can get my head around it, phase and temporal distortion seems to be the main concerns in designing audio cables, but for the life of me I don't see how conductor metallurgy has anything to do with this, but then again I am not really an expert in any field which would cover this.  From my understanding, conductor purity/metallurgy has an influence over signal propagation speed, but I have no idea how this would affect critical performance metrics (in my understanding) such as phase distortion.
 
You would think that cable manufacturers, given how ready they are to publish scientific justifications for their cable products, would participate more in threads such as this.  Presumably, given their marketing material, they must employ at least a couple of engineers or scientists.  When people start wrongly representing other products, more often than not a rep from the company notices and chimes in to set things straight.  Maybe we just need to drop a few company names?

 
Velocity of propagation relates to the geometry and the insulation of the cable.
 
In most interconnects the LCR is far too low to be of any consequence, i.e. it will not act as a low pass filter of any significance in the audio bandwidth.
 
If worrying about skin depth keeps you up at night, then 26 AWG solid core is a good choice. 
 
Try to find some comments from JNJN in this thread, he had some interesting stuff to say about all that.

 

[jnjn]

Quote:

These are really simple questions and you don't need access to a PHd or a particle accellerator to answer them.

Yah, but it helps..  Both electron accelerators, and heavy Ion..
Quote:

 
At audio frequencies at typical hookup distances, like for interconnect cables, those effects are trivial and can be ignored.  In general this can be ignored for audio purposes.  Sometimes for some specific purposes you need to be a little bit more careful though.

One of these days, I'm going to have to fix that wiki page..sigh..
Quote:

Was reading Stereophile and they were talking about swapping interconnects to "add warmth and smoothness". Seriously, why do I still have a subscription with them?

Because IC's can and do affect the sound.
 
When you have two IC's, one for left, and one for right, and the right channel puts 1 volt into the cable, pushing 100 microamps of current into the 10k load at the amp end, what path do you think that current takes to get back to the preamp?
 
If it's RCA's unbalanced with class 2 equipment, the return is 50% via the right shield, and 50% left shield at low frequency.  If there are safety grounds and 3 prong IEC's, the bulk of the current goes via the third pin of the power cords at lf, changes to 50/50 in the IC's as frequency goes up, and to the signal braid at much higher frequency.
 
   Quote:

 
If you're going to apply transmission line theory at audio frequencies, then your load impedance must also be matched to the line impedance, otherwise, the whole exercise is rather pointless. What good is it to have say, a 100 ohm output impedance driving a 100 ohm line, only to have that line terminated with a 10k ohm load? Are you also modifying your equipment so that their input impedances match the line impedance?
 
And at what frequency are you determining the line's "characteristic impedance"? A cable won't start approaching it's mathematical "characteristic impedance" until you're pretty well out of the audio range. Below that, the cable's impedance continuously rises.
 

se

Darn, was gonna add something...no need.
 
Quote:

 
Not sure where you got that understanding from. Velocity of propagation depends on the permittivity of the medium the signal is propagating through. Since there's no electric field below the surface of a conductor, this means that it's dependent on the medium surrounding the conductor.
 
Cables are minimum phase, so they won't cause phase distortion.
 
se

Vprop depends also on the permeability of the medium, unless the magnetic field is unconstrained.  Then you have to use EDC.  Of course, when half the return current is via the other ic's shield, the distributed inductance goes in the crapper, and the centroids of the paths open the system up to all kinds of loop area based interference..everybody seems to think that two parallel shielded cables connected between two chassis somehow tells the electrons which way to go..  You, buddy, I'm a left-channel electron, I ain't goin down that right hand braid..
Quote:

 
Velocity of propagation relates to the geometry and the insulation of the cable.
 
In most interconnects the LCR is far too low to be of any consequence, i.e. it will not act as a low pass filter of any significance in the audio bandwidth.
 
If worrying about skin depth keeps you up at night, then 26 AWG solid core is a good choice. 
 
Try to find some comments from JNJN in this thread, he had some interesting stuff to say about all that.

Nah, that joker doesn't know a thing..
 
jnjn

 

[liamstrain]

Quote:

Because IC's can and do affect the sound.
 
When you have two IC's, one for left, and one for right, and the right channel puts 1 volt into the cable, pushing 100 microamps of current into the 10k load at the amp end, what path do you think that current takes to get back to the preamp?
 

 
With the majority of consumer and professional audio equipment, and "regular" construction of commercial rca cables - would you say this is still a concern?