tweeter speaker wire - Page 6

You seem to have missed the third potential source of audible coloration in speaker wire, being inductance. And the fourth being skin effect.

As practical matters it is very rare for any of the 4 possible sources of treble loss to actually cause an audible difference:

(1) Capacitance
(2) Inductance
(3) DC resistance
(4) Skin effect of it you will high frequency AC resistance

However, all of them can have measurable effects and under extreme conditions, any might have an audible effect.

And that's only going to make a difference if the amp had a highish output impedance already and the speakers happen to have a difficult to drive (i.e. drops low) impedance.
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The output impedance of the amplifier need not be high for speaker wire with high resistance to cause an audible effect. If fine enough and long enough the wire can cause an audible effect all by itself.

For example, 30 gauge wire (hair fine wire) has a resistance of about 0.1 ohm per foot. A 5 foot 30 gauge speaker cable has 1 ohm resistance.

This is the impedance curve of a fairly ordinary reasonably-well designed speaker:



The speaker has a 14 ohm impedance (all resistive) at about 40 Hz. That causes only a 0.7 dB loss. Above about 200 Hz the speaker has an average impedance of about 5 ohms which leads to an loss that is about 1.5 dB. The difference in loss between these two areas leads to a clearly measurable and possibly audible (but probably not) response difference.

Poorly-designed speakers can cause greater response differences. Note that the example is very extreme - nobody in their right mind would use 30 gauge speaker cable. I think the thinnest wire ever sold for the use with speakers is 24 gauge, which has only abouta quarter as much resistance. Of course, if you run a 40 foot 24 gauge speaker cable then things are about twice as bad as my example.

They are generally tiny. They are miniscule compared to the time distortions that happen naturally during recording with microphones and playback via speakers.

In my experience differences like that go away as you tighten up your listening test methodologies.

like as in " only existing in my imagination?"

What is this timing **** about anyway? We are talking signals 20Hz to 20Khz, not in the MHz region. Get your scale correct.

The guy who used to wrap magic paper around his cables was funnier than this. Please try harder.

"some kind of" BS

http://www.st-andrews.ac.uk/~www_pa/Scots_Guide/audio/skineffect/page1.html
http://www.st-andrews.ac.uk/~www_pa/Scots_Guide/audio/skineffect/page2.html...and continue
http://www.st-andrews.ac.uk/~www_pa/Scots_Guide/audio/part7/page1.html ....and continue
http://www.st-andrews.ac.uk/~www_pa/Scots_Guide/audio/part7/page3.html :
As you might gather from this website, cables and their effect have little to do with what your opinion is, cable technology has to do with physics and math.
The only question is are any of the differences in the usual home environment and at the transmitted frequencies of any audible consequences - and no one in any attempt of a rigorous test has been able to show beyond chance that differences are discernible.
Edited by kraut - 12/25/12 at 11:50am

Well yes, for a time at least. In audio it's a ridiculous amount of cable. But for video, even standard NTSC video from your old VCR can be easily delayed by cable length. In fact your old NTSC TV had a delay line in the luminance path to "hold back" the B&W portion of the video signal while the chroma information was being demodulated. Every NTSC color TV ever made has a luminance delay line. The actual color demodulator circuits delay were in the single digit nanoseconds but the the band pass filters in the chroma channels were in the hundreds of nanoseconds. The filters had series inductors which is basically a long piece of wire, The delay line was also a long length of wire sometimes tapped along the way with capacitors. If this were not done you would see a noticeable B&W fringe on the edge of any colorful transition in the image*. In broadcast systems multiple video feeds into a switcher had to be timed as well. In the old days that was accomplished by making cable lengths equal. I understand Radar systems has similar timing requirements.

In another example look at a modern PC motherboard. You will no doubt see some copper traces that look like scope waveforms. Well this is physical length being added to that trace or wire to keep the signal it carries in time with another. Now, note I said modern PC motherboard. You won't see this on an old 8mhz PC. Why? Because those old PC's didn't have high enough buss clock frequencies to make timed wiring traces under a foot in length a factor. Today's PCs with buss speeds in the hundreds of megahertz require timed wiring even for a few inches in length.

So there you have it. Even though the speed of electrical signals travel at 66% light speed in a wire, it can be too long a time even in consumer electronics.

But again at audio frequencies the electrical delay introduced by wiring length is insignificant. It's all relative to the frequency of the signal.

*not to be confused with a convergence error. That's a different and very common CRT problem from the RGB beams not being in perfect registration.
Edited by Glimmie - 12/25/12 at 11:49am

No. The concentration of the signal in the outer layer of the wire is due to magnetic fields. But to re-iterate this is not an audible issue for speaker cables or interconnects carrying audio signals.


Don't overwork your imagination. The mistaken idea that audio signals might get scrambled in time within the same wire has been around for a long time and it is a fantasy.

The operative word being small as in very small, infinitesimal, irrelevant, inaudible.

Doesn't matter with regular analog audio signals.

1 milli = 1 /1000, one thousanth. (1 mSec)
1 micro = 1/1000000, one millionth. (1 uSec)
1 nano = 1/000000000, one billionth (1 nSec

The prop velocity of a signal along a cable is about 1 nano second per foot.
We can localize at about the 1 uSec range.
The prop velocity of sound is approximately 1 millisecond per foot.
In a little more detail...

There is a magnetic field which is within the wire caused by the current that travels in the wire. As the frequency increases, the time varying magnetic field within the wire will create a toroidal current in the metal of the wire. This current will be opposite the wire current at the center of the wire, and in the same direction at the surface of the wire. As a result, the current will be less in the center, more at the surface. As the frequency increases, this effect becomes greater.

This effect also includes the current of the other conductor in the circuit...but instead of calling it skin effect, it is called proximity effect. The physics is the same however. The current is always trying to take the least reactive path,
jn

You might be interested in reading an article written about two decades ago about the effects of using different speaker cables at http://www.theaudiocritic.com/back_issues/The_Audio_Critic_16_r.pdf starting at page 51. (pdf page 39)
He does mention using a coaxial cable near the end of the article, but you'll probably enjoy it more if you read it from start to finish because it's always more interesting if you learn something new along the way.
(Note: his examples are for longer lengths of wire than you are considering, so all the effects he's noted would be reduced in your application)

A word of warning, this may be hard to read because:
a) he's not always systematic when going from one cable to the next. (Ex: doesn't go from lowest resistance to highest)
b) his writing style may come off as being somewhat angry/arrogant because he has absolutely no patience for people who form subjective opinions about the way things sound in audio.

If you can read it without being offended then you should pick up enough facts to form your own opinions on why speaker cables sound the way they do.
(you might even choose to change your viewpoint on some long held beliefs)
Edited by stereo2.0 - 12/27/12 at 3:47am

I choose C...the use of approximations without regard to accuracy.

jn

It would be nice if the quoted text were accurate with respect to the discussion of a current carrying conductor.

It must be understood that the quote on skin depth is an accurate description of e/m waves impinging on a conductive planar surface and within a waveguide.

It is not however, an accurate description of what happens when the fields are generated by a current within the conductor.

That actual verbage is what got Hawksford in trouble back in '85.

jn

I was responding to this question which seemed to be concerned with the skin effect.

Maybe this quote is more precise when it comes to conductors (and not waveguides):

http://www.wheeler.com/technology/technicalpaper2/technicalpaper2.pdf

http://www.ultracad.com/articles/skin%20effect.pdf

That content is better with respect to describing what happens. The why is not described there, but that is probably for the best..

jn

Don't want to go there...my physics schooling is rudimentary at best...and my math was nothing beyond calculus and vectors....and about forty years ago.