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17 minutes ago, stereo coffee said:

Therefore if we want nothing that adds to create reactance, in- between our source and power amp,  resistance we know is free of reactance, suggests as being ideal.   The form this takes is known as impedance bridging:   https://en.wikipedia.org/wiki/Impedance_bridging

So you don't wan't anything with reactance between your source and the PA, you have two choices:

 

A resistor voltage divider circuit, or a very loud listening session.

 

Edit: Dang, I forgot about those pesky reactance filled interconnect leads...

Edited by bob_m_54
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37 minutes ago, bob_m_54 said:

It's neither bad nor good, it just is.

It is bad. Always bad.

Like cancer. It just is but it is always bad.

Unless you do not like someone, like Rupert. Then you could reasonably think it is good. 😉

 

20 minutes ago, stereo coffee said:

Therefore if we want nothing that adds to create reactance, in- between our source and power amp,  resistance we know is free of reactance, suggests as being ideal.

So when your cables change the sound of the system (even if you think for the better) then it is the reactance at play.

Reactance purposely introduced by the manufacturer to differentiate them in the market. 

It can be nothing else, regardless of whether it is "the big bulge" on the cable, different dielectric used, additions to copper, anything.

 

Good - engineering wise - cables would have had both capacitive and inductive reactance minimised, so that their impedance would have been virtually resistance only and result with the transfer of signal that is unchanged, other of the minute loss of energy on the resistance.

From above it is clear that if particular set of cables have any discernible impact on sound, they are (technically) faulty.

And it is not a challenge to make cables that have no impact on sound.

Any, even mildly involved in electronics person knows that since forever and is the reason why electronics technicians and engineers normally do not invest a lot in cables and are sceptic as to the benefits of doing so.

For cables are passive devices and if they are non-linear (and they are if they have impact on sound), then they are distorting and hence are faulty.

 

We put up with distortion in active devices (valves and transistors) for they are inherently non-linear, but for passive and linear devices there is no need to.

This shows the futility of so called "cable wars". People use fancy, reactive cables because they like them and because it involves them in the hobby.

 

For those who disagree with the above, I recommend switching to one of these these amps like Audiolab, where there is both pre-amp output and power amp input. One can join the two together with their favourite sounding cable and improve the sound, or even change that cable every day to have a different sound flavour every day.

 

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35 minutes ago, bob_m_54 said:

So you don't wan't anything with reactance between your source and the PA, you have two choices:

 

A resistor voltage divider circuit, or a very loud listening session.

 

Edit: Dang, I forgot about those pesky reactance filled interconnect leads...

A resistor voltage divider which is variable is possibly easier to adjust for preferred listening level.  It goes without saying that observing best design of cables,  to minimize reactance, and conductivity,  is also rewarding. 

 

The elephant in the room so to speak is the reactance, sometimes presumed invisible,  to unnecessarily change voltage upward to suit sensitivity different to consumer line level.  

 

 

 

 

 

Just now, stereo coffee said:

A resistor voltage divider which is variable is possibly easier to adjust for preferred listening level.  It goes without saying that observing best design of cables,  to minimize reactance, and assist conductivity,  is also rewarding. 

 

The elephant in the room so to speak is the reactance, sometimes presumed invisible,  to unnecessarily change voltage upward to suit sensitivity different to consumer line level.  

 

 

 

 

 

 

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1 hour ago, rockeater said:

 

For cables are passive devices and if they are non-linear (and they are if they have impact on sound), then they are distorting and hence are faulty.

 

We put up with distortion in active devices (valves and transistors) for they are inherently non-linear, but for passive and linear devices there is no need to.

 

 

I would argue that cables are by and large linear, at least within their intended operating ranges. If they have non-negligible inductances or capacitances they will introduce linear distortions.

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5 hours ago, rockeater said:

It is bad. Always bad.

Like cancer. It just is but it is always bad.

Unless you do not like someone, like Rupert. Then you could reasonably think it is good. 😉

 

So when your cables change the sound of the system (even if you think for the better) then it is the reactance at play.

Reactance purposely introduced by the manufacturer to differentiate them in the market. 

It can be nothing else, regardless of whether it is "the big bulge" on the cable, different dielectric used, additions to copper, anything.

 

Good - engineering wise - cables would have had both capacitive and inductive reactance minimised, so that their impedance would have been virtually resistance only and result with the transfer of signal that is unchanged, other of the minute loss of energy on the resistance.

From above it is clear that if particular set of cables have any discernible impact on sound, they are (technically) faulty.

And it is not a challenge to make cables that have no impact on sound.

Any, even mildly involved in electronics person knows that since forever and is the reason why electronics technicians and engineers normally do not invest a lot in cables and are sceptic as to the benefits of doing so.

For cables are passive devices and if they are non-linear (and they are if they have impact on sound), then they are distorting and hence are faulty.

 

We put up with distortion in active devices (valves and transistors) for they are inherently non-linear, but for passive and linear devices there is no need to.

This shows the futility of so called "cable wars". People use fancy, reactive cables because they like them and because it involves them in the hobby.

 

For those who disagree with the above, I recommend switching to one of these these amps like Audiolab, where there is both pre-amp output and power amp input. One can join the two together with their favourite sounding cable and improve the sound, or even change that cable every day to have a different sound flavour every day.

 

so invent some capacitors and inductors that don't display reactance..

 

Edit: wtf is Rupert?

Edited by bob_m_54
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3 hours ago, Steffen said:

 

I would argue that cables are by and large linear, at least within their intended operating ranges. If they have non-negligible inductances or capacitances they will introduce linear distortions.

certainly not linear with respect to frequency

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11 minutes ago, bob_m_54 said:

 

certainly not linear with respect to frequency

 

In what sense, are there cables that introduce non-linear distortions?

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1 minute ago, Steffen said:

 

In what sense, are there cables that introduce non-linear distortions?

Both capacative and inductive reactance are frequency dependant.

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4 hours ago, Steffen said:

I would argue that cables are by and large linear, at least within their intended operating ranges. If they have non-negligible inductances or capacitances they will introduce linear distortions.

Good ones obviously have negligible reactance.

But others, the ones that change (or "improve") the sound, must have such non-negligible reactance if indeed they alter the sound.

How else would piece of wire do it otherwise?

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1 hour ago, bob_m_54 said:

Both capacative and inductive reactance are frequency dependant.

 

Oh, definitely, they behave as low-pass or high-pass filters (in conjunction with the input or output impedances of the attached equipment). So, they will roll off the high or low end of the spectrum. But those are linear distortions.

 

I’m not aware of any cable effects that would add frequencies to the signal that weren’t there before. That would be non-linear distortions, examples would be harmonic distortions or intermodulation distortions. Those are almost always caused by active components (any kind of semiconductor or valve), because passive components typically lack the sort of non-linear behaviour necessary for this.

 

EDIT: One notable exception I just remembered are non air-cored coils and transformers. Iron and ferrite cores can indeed introduce nonlinearities

.

 

36 minutes ago, rockeater said:

Good ones obviously have negligible reactance.

But others, the ones that change (or "improve") the sound, must have such non-negligible reactance if indeed they alter the sound.

 

No argument there, but I was responding to the assertion that cables aren’t linear, not that they don’t have a flat frequency response.

 

 

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21 hours ago, Steffen said:

 

Oh, definitely, they behave as low-pass or high-pass filters (in conjunction with the input or output impedances of the attached equipment). So, they will roll off the high or low end of the spectrum. But those are linear distortions.

 

I’m not aware of any cable effects that would add frequencies to the signal that weren’t there before. That would be non-linear distortions, examples would be harmonic distortions or intermodulation distortions. Those are almost always caused by active components (any kind of semiconductor or valve), because passive components typically lack the sort of non-linear behaviour necessary for this.

 

EDIT: One notable exception I just remembered are non air-cored coils and transformers. Iron and ferrite cores can indeed introduce nonlinearities

.

 

 

No argument there, but I was responding to the assertion that cables aren’t linear, not that they don’t have a flat frequency response.

 

 

 

Cables don't have a flat frequency response because reactance isn't linear. If cables were purely resistive, they would have a flat frequency response.

 

Edit: I agree that the non linearity at audio frequencies, given the values of capacitance and inductance, would be small, but it is there.

 

oops 2nd Edit: I didn't mention anything about "introduced frequencies", I don't know how you arrived there.

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21 minutes ago, bob_m_54 said:

 

Cables don't have a flat frequency response because reactance isn't linear. If cables were purely resistive, they would have a flat frequency response.

 

Your post's words are similar to the findings  by Cyril Bateman    https://www.proaudiodesignforum.com/images/pdf/Cyril_Bateman/Bateman_Speaker_Amp_Interaction_pt1_only.pdf  which infers it is the frequency content which varies the reactance, with reactance as I understand when present, also then awkwardly influencing the resistance.  Cyril provides examples of cables which exhibit less reactance, which are therefore better for audio reproduction purpose. He also proposes a zobel network at the speaker end of the speaker lead to seek to improve audio performance.

 

He also finds what I understand as a reactance from the low amplifier impedance then interacting with the speaker cable itself. 

 

"Capacitance, resistance and inductance also vary with frequency, depending on the cable insulation and wire dimensions used."

 

 

 

 

 

 

 

 

 

 

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2 minutes ago, stereo coffee said:

 

Your post's words are similar to the findings  by Cyril Bateman    https://www.proaudiodesignforum.com/images/pdf/Cyril_Bateman/Bateman_Speaker_Amp_Interaction_pt1_only.pdf  which infers it is the frequency content which varies the reactance, with reactance as I understand when present, also then awkwardly influencing the resistance.  Cyril provides examples of cables which exhibit less reactance, which are therefore better for audio reproduction purpose. He also proposes a zobel network at the speaker end of the speaker lead to seek to improve audio performance.

 

He also finds what I understand as a reactance from the low amplifier impedance then interacting with the speaker cable itself. 

 

"Capacitance, resistance and inductance also vary with frequency, depending on the cable insulation and wire dimensions used."

 

 

 

 

 

 

 

 

 

 

 

I don't know about Cyril Bateman, but that is basic AC electronics theory.

 

Oh, and just because I'm a bit pedantic, capacitance and inductance won't change with frequency, but their reactance will change.

 

(pure) Resistance will remain constant, and will only be affected by heat.

 

And, of course, inductance and capacitance will be determined by cable configurations/dimensions , such as length, thickness of conductors, and distance between conductors, Insulation types will have very little affect at audio frequencies, but the thickness will determine how far apart the conductors will be.

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11 minutes ago, bob_m_54 said:

but that is basic AC electronics theory.

 

Very basic, even if somewhat strangely restated.

 

12 minutes ago, bob_m_54 said:

Oh, and just because I'm a bit pedantic, capacitance and inductance won't change with frequency, but their reactance will change.

 

Yep

 

12 minutes ago, bob_m_54 said:

(pure) Resistance will remain constant, and will only be affected by heat.

 and maybe cosmic particles :)     but the point is that resistance does NOT change with frequency (mis-stated above)

 

24 minutes ago, stereo coffee said:

with reactance as I understand when present, also then awkwardly influencing the resistance.

 

NO way can reactance change resistance.  Perhaps you meant impedance??  

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5 minutes ago, aussievintage said:

 

Very basic, even if somewhat strangely restated.

 

 

Yep

 

 and maybe cosmic particles :)     but the point is that resistance does NOT change with frequency (mis-stated above)

 

 

NO way can reactance change resistance.  Perhaps you meant impedance??  

I can't multiquote sorry, but..

 

Yeah I didn't read the PDF, too much energy required..

Cosmic particles will only affect it if you have carbon fibre patterned tape on them..

And yes, possibly he meant to say impedance...

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As well as Capacitance and Inductance representing reactance, measured resistance  of cables is seen to  change upward in its resistance value at higher frequencies.  As example here discussing the skin effect of cables. https://en.wikipedia.org/wiki/Skin_effect#cite_note-Reeve558-20

we see quite a change of 827.17 ohms added between 1 Hz to 5Mhz for telephone cable of 24 gauge dimension

 

This was also seen in the Cyril Bateman article where he tabulates two cable types more related to audio use, showing differing resistance at frequencies between 1Khz and 2Mhz

 

I find it always good to know what happens outside of normally thought of boundaries, as what happens there can  provide insight into the bigger picture.

 

Screenshot from 2021-02-27 22-51-24.png

Screenshot from 2021-02-27 23-07-30.png

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Creating a sound system can be compared to building a house (something I know a lot about). 

 

What is the most important part of  building a house - the foundations, get that wrong and one day you won't have a house but a pile of crap.

 

For years I have seen the b/s argument about the 'quality' of the electricity that the power company supplies. So, the voltage varies, there are spikes and the know alls throw up their hands in despair - why. Buy a pure sine wave inverter, the type that uses a massive Tx. with AVR - automatic voltage regulation, + or - 1% accuracy,  choose what type of batteries you like, deep cycle golf cart ones or other, graphite batteries are around the corner 50 - 100 times the storage power of conventional batteries.

 

What does this give you -clean, spike free, accurate voltage  electricity and not just for a sound system but for all electrical appliances which will last a lot longer . The implication for PSU design will be radical - AFAIK no one has explored this route - why not. This is not theoretical rocket science - why do I not see any actual PSU designs to take advantage of something that has been known about for decades - the inertia effect, just like the totally out of date connectors, RCA, XLR, headphone jacks, completely ignoring sound science.

 

Would you knowingly put contaminated petrol/diesel into your car, well would you? all this talk about amp design but nothing on the very thing that carries the electrical information from one piece of equipment to another, not sexy, ignore. Just how much of the original signal information get's lost or corrupted before it even reaches the speakers/h/phones. Should'nt this be the start point - rational replies please.

 

 

 

 

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5 hours ago, bob_m_54 said:

 

oops 2nd Edit: I didn't mention anything about "introduced frequencies", I don't know how you arrived there.

 

That’s what sorts linear systems from non-linear ones. If you think a linear system is one with a frequency response flat as a ruler you’re mistaken.

 

Cables are essentially RLC networks, and as long as neither of those three constituents are non-linear (through effects such as magnetic remanence or dielectric absorption, for example), this means they are linear systems. They will only introduce linear distortions (amplitude and phase changes dependent on frequency), but no non-linear distortions (like harmonics).

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5 hours ago, stereo coffee said:

we see quite a change of 827.17 ohms added between 1 Hz to 5Mhz for telephone cable of 24 gauge dimension

Telephone cable?

The ones designed to attenuate anything above 3kHz?

You are giving here on audio forum where we talk about systems that work on 20Hz to 20kHz and example of cable designed to cut above 3kHz with signal of 5 MHz?

It is like "...in space no one can hear you scream" 😉

 

 

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4 hours ago, Southerly said:

AFAIK no one has explored this route - why not (power re-generation or conditioning)

I have some 30 years ago.

We had those 240 to 240V saturated core Power Conditioners at work to make sure that the telemetry monitoring fire alarms did not surfer from power supply spikes.

Big, heavy things.

I picked one of the new ones for it did not hum and buzz too much and I brought it home.

Put it in the bathroom next to the listening room, so that I wouldn't be bothered by the ever so slight hum at night.

The music just went lifeless. There was no punch, no attack, no kick, no slam.

Clean power, but too slow to respond to an amp with 1µs rise time.

And this is the problem with most power conditioning / re-generating systems. They are too slow.

But might be good if you live close to an industrial area and happen to be listening to ballads for acoustic guitar and voice or 18th century choral music.

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2 hours ago, rockeater said:

Telephone cable?

The ones designed to attenuate anything above 3kHz?

You are giving here on audio forum where we talk about systems that work on 20Hz to 20kHz and example of cable designed to cut above 3kHz with signal of 5 MHz?

It is like "...in space no one can hear you scream" 😉

 

 

In electronics where question is made of whether in this case with cables the properties of resistance changes with frequency, it is one to examine very broadly, the criteria is widened to be.... CAN it ever occur, rather than it does not occur where I think it nicely should, therefore we can reach conclusion it does not occur.  The reason for  this is the wider physics properties can be having influence on the lower.  

 

If we view cable research conducted by Cyril Bateman, he like many others *, is not convinced or trapped at all ,  by limiting frequency, and you can see from the tests he conducts the frequencies that are much higher, are then influencing the frequencies we do hear, which would otherwise be undiscovered, and be leading to perplexing results, if he had limited his criteria.

 

* http://recordinghacks.com/articles/the-world-beyond-20khz/

 

Interesting as we have been discussing cable reactance is to see what happens with moving magnet and moving coil cartridges where inductance has  influence on frequency response.

 

We are though still not seeing the elephants in the room, as example @Southerly informing of better ways of doing AC power, and as I have pointed out if we are to properly hear our source equipment, we should look more to the properties of resistance, by certainly getting cables right with minimal reactance, but more so seeing what is presently as reactance between our source and power amp.

 

 

 

 

 

 

 

 

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26 minutes ago, sir sanders zingmore said:

The article is tagged with this line

Using a study of the human hearing mechanism as his foundation..”

but I could find no link to this study 

 

I understand David Blackmer is referring to the 4 books mentioned at the foot of the article.

Screenshot from 2021-02-28 11-13-27.png

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1 hour ago, stereo coffee said:

I understand David Blackmer is referring to the 4 books mentioned at the foot of the article.

Screenshot from 2021-02-28 11-13-27.png

Ahah

so rather than providing a direct link to his unproven and contentious claims about hearing (which just happen to support the product he sells), we are expected to read four books on the subject. 
 

The actual arguments he presents are completely anecdotal and really not befitting a company that makes measurement equipment. 

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22 minutes ago, sir sanders zingmore said:

Ahah

so rather than providing a direct link to his unproven and contentious claims about hearing (which just happen to support the product he sells), we are expected to read four books on the subject. 
 

The actual arguments he presents are completely anecdotal and really not befitting a company that makes measurement equipment. 

Thanks for your opinion, it can easily be seen he is and was,  a legendary figure in audio.

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4 hours ago, stereo coffee said:

we should look more to the properties of resistance, by certainly getting cables right with minimal reactance, but more so seeing what is presently as reactance between our source and power amp

 

 

Resistance and reactance are independent from each other, and taken together, make up the impedance of the cable. This is relatively easy* to measure, and allows us to quite accurately predict the frequency response out of a given source impedance, though the cable, into a given load impedance.

 

* resistance measurement may require a long cable run, because most ohm meters aren’t good at the low ranges we’re faced with here

 

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36 minutes ago, Steffen said:

 

Resistance and reactance are independent from each other, and taken together, make up the impedance of the cable.

 

 

Don't you mean ... "Resistance and inductance are independent from each other, and taken together, make up the impedance of the cable."?

 

Andy

 

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Quote

 

Goodness gracious me.

 

Tweeter which have the same frequency response to 20khz.... but differ between 20 and 40khz.

 

a)   Have differing phase response below 20khz

 

b)   Will have different energy/time response at most if not all frequencies

 

c)  Basically don't exist anyways.....  tweeters almost always differ in frequency response by at least 1dB or more over all frequencies.... especially when polar response/coverage pattern is taken into consideration.

 

 

Ergo the tweeters sound different due to differences below 20khz.

 

He begins with the premise that they are the same below 20khz.   That is ridiculous.

 

 

 

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14 minutes ago, davewantsmoore said:

 

 

 

 

He begins with the premise that they are the same blow 20khz.   That is ridiculous.

 

 

 

However qualifies as well that a number of tweeters had been tested   "  The best of these had virtually identical frequency response to 20kHz, yet they sounded very different."

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12 minutes ago, stereo coffee said:

However qualifies as well that a number of tweeters had been tested   "  The best of these had virtually identical frequency response to 20kHz, yet they sounded very different."

 

Yes.

 

Firstly .... I put it to him that they didn't have virtually identical frequency response.....  they differed by more than +/-1.5dB over their range  (ie. difference of large Q)

 

Secondly.... they have different energy/time responses.... and different phase responses.

 

Beginning with the premise (and a hand wave) that "they are the same below 20khz" is utter nonsense.

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42 minutes ago, stereo coffee said:

However qualifies as well that a number of tweeters had been tested   "  The best of these had virtually identical frequency response to 20kHz, yet they sounded very different."

 

as I said, anecdotal testing 

2 hours ago, stereo coffee said:

Thanks for your opinion, it can easily be seen he is and was,  a legendary figure in audio.

 

appeal to authority

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28 minutes ago, davewantsmoore said:

 

Yes.

 

Firstly .... I put it to him that they didn't have virtually identical frequency response.....  they differed by more than +/-1.5dB over their range  (ie. difference of large Q)

 

Secondly.... they have different energy/time responses.... and different phase responses.

 

Beginning with the premise (and a hand wave) that "they are the same below 20khz" is utter nonsense.

The system he used for measuring is this one :  https://wiki.analog.com/resources/tools-software/sigmastudio/toolbox/systemschematicdesign/speakerresponsemlssa

 

Were you with him that day ?

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1 hour ago, andyr said:

Don't you mean ... "Resistance and inductance are independent from each other, and taken together, make up the impedance of the cable."?

 

 

No.  inductance is not the same as inductive reactance,  the latter changes with frequency. 

 

inductive reactance = 2 * Pi * freq *inductance

 

Then there is capacitance, and capacitive reactance, similar relationship, except capacitive and inductive reactance  are 180 degrees apart, resistance being in the middle, 90 degrees from both and impedance is the combination of resistance, inductive, and capacitive reactance.

 

Basic electronics people.

 

https://circuitglobe.com/difference-between-resistance-and-reactance.html

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20 hours ago, stereo coffee said:

As well as Capacitance and Inductance representing reactance, measured resistance  of cables is seen to  change upward in its resistance value at higher frequencies.  As example here discussing the skin effect of cables. https://en.wikipedia.org/wiki/Skin_effect#cite_note-Reeve558-20

we see quite a change of 827.17 ohms added between 1 Hz to 5Mhz for telephone cable of 24 gauge dimension

 

This was also seen in the Cyril Bateman article where he tabulates two cable types more related to audio use, showing differing resistance at frequencies between 1Khz and 2Mhz

 

I find it always good to know what happens outside of normally thought of boundaries, as what happens there can  provide insight into the bigger picture.

 

Screenshot from 2021-02-27 22-51-24.png

Screenshot from 2021-02-27 23-07-30.png

 

haha, I knew straight after I typed it, it was going to come back and bite me.

Yes, in your example of a 24AWG cable at 100KHz, there is a full 20 ohm increase on resistance, due to skin effect. Interesting to note that the chart shows the increase at 10KHz is less than 50 milliohms/Km.

 

But getting back to Audio Frequencies, where you have say 14 AWG copper speaker cable. The increased AC resistance between DC and 20KHz, is app 1 ohm/Km ie from 13 ohms Rdc to 14 ohms Rac.

 

Bring that back to a realistic length of say 10M, and it's about 10 milliohms. Your combined contact resistance at the terminals is likely to be about that.

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5 hours ago, andyr said:

 

Don't you mean ... "Resistance and inductance are independent from each other, and taken together, make up the impedance of the cable."?

 

Andy

 

 

Like @aussievintage already pointed out, both inductance and capacitance lead to reactance. Reactance is the imaginary* part of the impedance of a cable, with resistance being the real* one.

 

* Both “imaginary” and “real” in their math/engineering meaning, of course

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19 minutes ago, Steffen said:

Like @aussievintage already pointed out, both inductance and capacitance lead to reactance. Reactance is the imaginary* part of the impedance of a cable, with resistance being the real* one.

 

* Both “imaginary” and “real” in their math/engineering meaning, of course

 

 

Yep.  If you are still unsure, remember the units.  Inductance is measured in Henries.  You can't mathematically add that to resistance which is in ohms . However, inductive reactance is in ohms , so it can be added to form impedance..  Note however, it is a vector at a different angle (90 degrees) to resistance, so vector maths is needed

 

image.png.41e9c507ef2dc5f21f309e0a1b8b5614.png

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4 hours ago, aussievintage said:

 

Then there is capacitance, and capacitive reactance, similar relationship, except capacitive and inductive reactance  are 180 degrees apart, resistance being in the middle, 90 degrees from both and impedance is the combination of resistance, inductive, and capacitive reactance.

 

 

Understood - thanks, av.

 

Talking only about spkr cables - these will have a resistance, inductance and capacitance measurement.

 

My understanding is that high inductance is not good for a spkr cable - as spkr cables can carry a lot of current ... and inductance acts as a brake on current.  So the ideal spkr cable has very low inductance?

 

Unfortunately low inductance carries with it the penalty of high capacitance - and whereas capacitance doesn't affect current ... it does have an affect on the amplifier driving the spkr cables!

 

Is my thinking correct, here - or am I thinking this wrongly?

 

Andy

 

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10 minutes ago, andyr said:

My understanding is that high inductance is not good for a spkr cable - as spkr cables can carry a lot of current ... and inductance acts as a brake on current.  So the ideal spkr cable has very low inductance?

 

Not a brake  It's just a very small addition to the impedance.  The higher the inductance and the higher the frequency, the higher the reactance.  Luckily, without coiling a wire, inductance remains quite low.  The small amount of reactance in any decent normal speaker cable is not worthy of the debate surrounding it. 

 

13 minutes ago, andyr said:

Unfortunately low inductance carries with it the penalty of high capacitance -

 

Not at all.  No relationship inherent in those properties.  Coils vs parallel conductors/plates.   However,  you might design a cable construction method that indeed causes a relationship as you describe.     

 

14 minutes ago, andyr said:

and whereas capacitance doesn't affect current

 

Not true either.  Capacitive reactance in a cable shunts current bypassing the speaker, but the amount is again frequency dependant and small.  Combined with low speaker impedances, the tiny shunt is not worth worrying about for most intents and purposes.

 

 

 

 

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