Hi Everyone,
There's a lot of discussion about practical limits of cable design in theory, and I realize that it's because we are discussing pure theory that little new ground is getting laid, or broadly shared consensus.
For those of you with an engineering bent, would you take a look at this review's measurements and results?
Wireworld Eclipse 5 and Silver Eclipse 5 Audio Cables - HomeTheaterHifi.com
He seems to do a pretty thorough job and to me seems to conclude the speaker cables have very low inductance and capacitance. What are your thoughts? Am I misreading? Is there a big trade off between R, L or C that I missed?
Best,
Erik
There's a lot of discussion about practical limits of cable design in theory, and I realize that it's because we are discussing pure theory that little new ground is getting laid, or broadly shared consensus.
For those of you with an engineering bent, would you take a look at this review's measurements and results?
Wireworld Eclipse 5 and Silver Eclipse 5 Audio Cables - HomeTheaterHifi.com
He seems to do a pretty thorough job and to me seems to conclude the speaker cables have very low inductance and capacitance. What are your thoughts? Am I misreading? Is there a big trade off between R, L or C that I missed?
Best,
Erik
The most important parameter for conventional speaker cables is resistance.
If resistance is extremely high, it can add additional frequency response variations to the response of the speakers. This is generally not all that significant as speakers and rooms generally have even greater frequency response variations.
Resistance is most important because it affects all frequencies equally. The effect may vary with frequency but they do so because the impedance of the loudspeaker varies with frequency.
Inductance and capacitance primarily affect high frequency response, if they have any audible effects at all. Usually the high frequency effects relate to just supersonic frequencies.
Many unconventional cables make claims about reducing resistance, inductance, capacitance, and/or skin effect. Unless you have some pretty atypical speakers, or very long or very poor (numerically large wire gauge) cables, actual audible problems due to them is rare.
For example my speaker cables have generally been number 12 zip cord about 8 feet long. Whenever I measured them, their effect on system frequency response was insignificant - like a fraction of a dB.
That is a very high capacitance cable. Twisted pair cables are around the 10pF/ft mark.
You cannot have low capacitance AND inductance at the same time
You cannot have low capacitance AND inductance at the same time
Thanks David! Thats exactly the kind of eyes on feedback I was looking for!
What's zip cord capacitance normally? Say a decent, fine stranded 14 guage?
Best,
Erik
What's zip cord capacitance normally? Say a decent, fine stranded 14 guage?
Best,
Erik
Huh? both inductance and capacitance are related to the following:
x=LN d(outer conductor)/d(inner conductor).
See, this is the kind of discussion that doesn't help. People start talking about principles, and theory without actually answering the original question.
If you really want to promote science and engineering, LOOK at the question.
Erik
If you really want to promote science and engineering, LOOK at the question.
Erik
Inductance is related to cosh-1(S/d) where S is separation and d is conductor diameter
Capacitance is related to 1/cosh-1(S/d)
Closer spacing means capacitance goes up but loop area goes down and inductance goes down,
Capacitance is related to 1/cosh-1(S/d)
Closer spacing means capacitance goes up but loop area goes down and inductance goes down,
I am suspicious of the OP linked review because the statement that it is a low capacitance cable is so absolutely wrong. It is a cosmetically attractive way of building a multiple parallel pair cable, similar in principal the the so called "cat-5" speaker cables. These can sound different due to the high capacitance and sometimes the amplifier stability problems they may cause
The question seems to have its problems as it seems to be all about measurements and says very little about actual reliably perceived sound quality.
Of course talking about actual reliably perceived sound quality isn't much fun because it tends to be much more similar than the 4th decimal place in some abstract measurement.
For example:
https://web.archive.org/web/20140704140807/http://www.nousaine.com/pdfs/Wired%20Wisdom.pdf
HAHAHA. Hahaha, god, that's funny. That's exactly the difference between so-called scientists and engineers and real ones. They offer a facsimile of rational thought but in fact are hugely driven by emotion. Their emotions prevent them from actually listening. This happens in medicine and politics as well. No discipline is immune to this effect.
Even though my question was pretty straightforward about numbers, processes, tools and materials the person answering decided for all of us that another topic, perceived sound quality, was more important and therefore all that should be discussed. In a sense, this person's gut desire to talk about something entirely different attempted to hijack the thread.
See, a real engineer would have answered something like this:
And then he would have interjected his own analysis:
or....
or....
I should use this as a thesis for "scientific elitism." What are the symptoms?
- Lack of respect for others.
- Inability to listen.
- Certain that their knowledge is all that is known or can be known.
- The use of science/engineering as an excuse for these three behaviors.
By the way, my using the term "real engineer" was a bit of a troll, and example of what not to do. Using labels to promote conformity.
Thanks,
Erik
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Well, I gave you an overview of the biggest problem with the review, and you turned it into a joke.
As a technical review it has its problems, too.
However, every time someone makes a science-based technical comment, you seem to miscast it as being just "Their position on the topic".
Bottom line, why should anybody help you by putting effort into this project just to have their comments dismissed and joked about?
Erik, if you want good explanations, I'd suggest digging up the comprehensive papers from Dick Greiner and Fred Davis (these were mostly done about 30-35 years ago). No need to rehash their results here, go to the (reliable) sources.
Hi Sy.
Thanks for the references. I will read those but I might not end up with very well informed conclusions. In this case, experience matters, so I was hoping that a kind soul would look at the review and at least discuss the electrical measurement principles and conclusions about phase angles for instance. Like "there's no way those measurements would have caused that much phase shift..." or something.
I didn't realize I was asking for that much effort. Only one person has answered saying the cables seem really high in capacitance, which is a perspective I just wont' have, but was hoping others here might have done some amount of experimentation they'd be willing to share.
Best,
Erik
The RF characteristic impedance of a cable is given by sqrt(L/C), where L and C are both measured per unit length (metres for most people, feet for Americans). For most cables this is going to be in the range 10-200 ohms.eriksquires said:
The RF propagation speed of a cable is given by 1/sqrt(LC) units per second (again, metres or feet depending on how you measured L and C). You can't go faster than the speed of light, and most cables are somewhat slower than this. This means that you can't have simultaneously low L and C. There is no way round this, no matter how much money you spend or how weird a cable design you use.
For loudspeaker use about the only thing which matters is R, which should be as small as reasonably possible. L and C should not be unusually large or small, compared with 'normal' cables.
And I believe the math. However, it's still not exactly what I'm asking which is more related to experience with measuring real cables.
I'm wondering if you have measured speaker cables, and whether this person's measurements sound reasonable, and if this cable looks "normal" or highly capacitive.
Best,
Erik
Heaviside condition
https://en.wikipedia.org/wiki/Heaviside_condition
Transmission line
https://en.wikipedia.org/wiki/Transmission_line
Transmission line theory only really matters for lines that are "wavelengths" long.
The wavelength of an audio signal is (lets say velocity factor is 0.5) L=0.5*3E8/10000 or 15km (~10 miles) for a 10kHz signal.... I agree with DF96 that the only thing that really matters much for speakers and audio signals is R.
Basically increasing spacing between conductors increases series inductance and reducing spacing increases parallel capacitance. Measure approx total capacitance by just hooking to a cap meter with far end disconnected, measure loop inductance by shorting the far end and measuring.
Fred Davis measured a lot of cables and if I recall correctly, 12Ga zip cord was in the sweet spot for zip cord with the typical insulation thicknesses used. The jumper cables were too inductive and smaller zip cord was more capacitive and higher resistance.
I did some measurements and our group did a listening test of speaker cables you can read about at: https://sites.google.com/site/audio...jects/april-2012-speaker-cable-listening-test
Stereophile did a writeup on it and there are a lot of interesting comments, including (IIRC) a calc of statistical significance by an interested party.
The Audio Society of Minnesota Conducts Cable Comparison Tests | Stereophile.com
https://en.wikipedia.org/wiki/Heaviside_condition
Transmission line
https://en.wikipedia.org/wiki/Transmission_line
Transmission line theory only really matters for lines that are "wavelengths" long.
The wavelength of an audio signal is (lets say velocity factor is 0.5) L=0.5*3E8/10000 or 15km (~10 miles) for a 10kHz signal.... I agree with DF96 that the only thing that really matters much for speakers and audio signals is R.
Basically increasing spacing between conductors increases series inductance and reducing spacing increases parallel capacitance. Measure approx total capacitance by just hooking to a cap meter with far end disconnected, measure loop inductance by shorting the far end and measuring.
Fred Davis measured a lot of cables and if I recall correctly, 12Ga zip cord was in the sweet spot for zip cord with the typical insulation thicknesses used. The jumper cables were too inductive and smaller zip cord was more capacitive and higher resistance.
I did some measurements and our group did a listening test of speaker cables you can read about at: https://sites.google.com/site/audio...jects/april-2012-speaker-cable-listening-test
Stereophile did a writeup on it and there are a lot of interesting comments, including (IIRC) a calc of statistical significance by an interested party.
The Audio Society of Minnesota Conducts Cable Comparison Tests | Stereophile.com
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In order: Yes, sort of (crap methodology, no controls or error bars, and no look at significance), somewhat more capacitive than zip cord.
This is a typical "audiophile" review, more focused on rationalizing spending a bunch of money and retelling a packaged story than actual analysis. Again, look at the work from decades ago- there's really not much more to be said.
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