[jneutron]

Thank you John.
So regardless of AWG of wire a single zip wire will have an impedence between 150-200?
Is it per feet ?
I was thinking of using Goertz M1 (http://www.goertzaudio.com/contents/en-us/d16_MI_Speaker_Cables.html)   instead of DYI wire since it has the lowest inductance value I know.I just noticed that the Impedence is 4. So I was planning to use Goertz M1 for HF and ZIP cord for LF since the capacitance of Goertz cable is 500pF /feet . But from this discussion it seems like Zip cord even with low capacitance offers higher impedence.
But going back to wikipedia the capacitance affect LF (copied from wikipedia)

 This table shows the capacitive reactance in ohms (higher means lower loss) for various frequencies and capacitances; highlighted rows represent loss greater than 1% at 30 volts RMS:


The voltage on a speaker wire depends on amplifier power; for a 100-watt-per-channel amplifier, the voltage will be about 30 volts RMS. At such voltage, a 1% loss will occur at 3,000 ohms or less of capacitive reactance. Therefore, to keep audible (up to 20,000 Hz) losses below 1%, the total capacitance in the cabling must be kept below about 2,700 pF.
Ordinary lamp cord has a capacitance of 10–20 pF per foot, plus a few picofarads of stray capacitance, so a 50 foot run (100 total feet of conductor) will have less than 1% capacitive loss in the audible range. Some premium speaker cables have higher capacitance in order to have lower inductance; 100–300 pF is typical, in which case the capacitive loss will exceed 1% for runs longer than about 5 feet (10 feet of conductor).
I am not sure at this point should I be looking at impedence of the wire vs each reactance seperate?

It states up front that it is loss.  It is not.  That table and that site is using approximations.  The discussion we are having is significantly beyond simple approximations.

If you make a cable with an impedance of 8 ohms and feed an 8 ohm speaker, there will be NO losses as a result of the cable capacitance.  It'll be in the 300 pf per foot range and 10 nH per foot, , but that is immaterial.   The cable will transfer all power with little loss out to the Mhz range.

Find out what the characteristic impedance of the cable you wish to try, then make one using zips.  Since the manu also uses the ideal Z as calculated by Z =sqr(L/C), you can use the same.  There, you can use 120 ohms for the zip as a good approximation.  if you need 12 ohms, use ten zips. 

Heck, you can even use cat5-e, it's 100 ohms.  need 4 ohms? Use 6 cables with all stripes tied together, all solids tied together.  Last year I used exactly that to transfer a 50 uSec 40 volt pulse with 10 uSec risetime to a 4 ohm load via a 15 foot cable.  Perfect transfer, no ringing or overshoot.

jn

ah, sorry..the characteristic impedance of a cable is independent of the length, so 120 or 100 ohm cable is intrinsic to the cable regardless of length.

[JerryLove]

The industry needs to meld localization theory with actual t-line theory, and actually learn how to measure high slew currents in low z systems.

Which industry? The Audio industry needs to measure the acoustics and psychoacoustics of reproduction; otherwise they risk inventing problems to solve and ignoring real ones in the process.

So then, it is your assertion that an impulse plot of pink noise will clearly show a midband delay of anywhere from 5 to 50 microseconds? (actually, we are sensitive to 1.2 uSec interchannel, but that is a discussion beyond the scope of the forum in terms of image stability)..

Assuming a triangle is a line to make the math easier, and using 2ns, that would mean that we were sensitive to movement of a sound source of 1/563-millionth of a foot. That would cause 2 uSec change in arrival time of sound.

Or does the slew need to be between frequency X and frequency Y (rather than L/R, which is what I presently understand from you)... in which case it could be reproduced with that move in driver spacing. Perhaps loosen a screw imperceptibly. 

And, if a switch is made from normal to biwire, that the composite soundfield modifications which result from driver to driver timing changes and consequent polar pattern changes in the 5 to 50+ microsecond range will be seen by a microphone?

The same as changing the driver alignment by 1/225-thousandth to 1/23-thousandth of a foot? That would make a 5-50microsecond change between two drivers.

ps.  Until the "industry" actually learns this stuff, nobody's gonna accurately measure anything along these lines.  That is why I mentioned the audibility test before.  If it discerns an audible difference in the mono setup, there may be one at the stereo level.  If not audible in the mono situation, there cannot be one in the stereo case.

Yea. I need to get to the store, grab some disposable wire and spend some time with that test. I have no good excuse, it's a practical test (with an admittedly impractical wire), but that I'm a procrastinator and it's functionally work.

[jneutron]

Wow.  In general, it is better to understand the topic before discussing it...sigh..

I could imagine why they would believe that. Kinda inferred from "inherent cable velocity"

Then you are also part of the "problem" so to speak.

The ONLY energy that can travel down a cable at the cable's inherent cable velocity, is energy that has the same "impedance" as the cable itself.

Which industry? The Audio industry needs to measure the acoustics and psychoacoustics of reproduction; otherwise they risk inventing problems to solve and ignoring real ones in the process.

The audio industry need to learn what it is the high end people are speaking about.  While measurement is great, I see little actual understanding in localization theory nor transmission line theory.  All I see is approximations.

Until that happens, they will be unable to answer this question:

What level of interchannel and intrachannel accuracy is required to stabilize virtual images in a +/- 60 degree soundfield generated by two speakers at +/-60 degrees.  IOW, what level of ITD and IID control is required.  And what level of change control in the wire impedance is required to allow that control between the amp and the load when the load impedance varies an order of magnitude?

Those who try to argue using numbers taken from earlier posts, yet not understanding what the numbers meant, is a waste of time and effort..

To wit: this gem..

Assuming a triangle is a line to make the math easier, and using 2ns, that would mean that we were sensitive to movement of a sound source of 1/563-millionth of a foot. That would cause 2 uSec change in arrival time of sound.

2 nSec is the inherent propagation velocity of a cable with an effective dielectric constant of 4.
2 uSec is the level of ITD humans are capable of resolving.

Or does the slew need to be between frequency X and frequency Y (rather than L/R, which is what I presently understand from you)... in which case it could be reproduced with that move in driver spacing. Perhaps loosen a screw imperceptibly. 

Not a bad question.  But you are using the head in vice argument, that is far too simplistic and inaccurate for the discussion.

Yea. I need to get to the store, grab some disposable wire and spend some time with that test. I have no good excuse, it's a practical test (with an admittedly impractical wire), but that I'm a procrastinator and it's functionally work.

OH, THAT"S RIGHT....I proposed that test to YOU....I forgot that.

C'mon, work is great!!!  I could watch it all day..

jn

[JerryLove]

Then you are also part of the "problem" so to speak.

I don't think you understood what I said.

The audio industry need to learn what it is the high end people are speaking about.  While measurement is great, I see little actual understanding in localization theory nor transmission line theory.  All I see is approximations.

They really don't. They need to understand what changes make perceptible improvements in the desirability of their products.

When we isolate solely for sound quality: the acid test is massed blind listening tests.

What level of interchannel and intrachannel accuracy is required to stabilize virtual images in a +/- 60 degree soundfield generated by two speakers at +/-60 degrees.  IOW, what level of ITD and IID control is required.  And what level of change control in the wire impedance is required to allow that control between the amp and the load when the load impedance varies an order of magnitude?

See: I think the question is "what changes make subjective improvements". Everything else is an attempt to explain perceived improvements or predict what paths would be most productive to experiment with.

To wit: this gem..2 nSec is the inherent propagation velocity of a cable with an effective dielectric constant of 4.
2 uSec is the level of ITD humans are capable of resolving.Not a bad question.  But you are using the head in vice argument, that is far too simplistic and inaccurate for the discussion.

The end result of everything you are discussing is that the sounds appear with a relative delay (L vs R, 100Hz vs 1000Hz, etc), yes? Wire X has one set of delays and wire Y has another set.

What is the order of magnitude for this delay? I suspect we can find other things that introduce similar amounts of delay, such as driver alignment. That would give us something in real, widespread use we could judge by.

[kinku]

If I have to use a Zobel with Goertz what should be the component values I should use. Found an interesting article.
 http://www.audioholics.com/reviews/cables/speaker-cable-reviews-faceoff-2/speaker-cable-reviews-faceoff-2-page-3
They recommend using 4.7ohm ,0.1uf for Zobel. Since I am DIYing it I thought I would include it. What type of resistor and capacitor I should go for?

[jneutron]

I don't think you understood what I said.

I understood exactly what you said.  Oddly enough, your post no longer contains the erroneous statement I responded to in full.
this one:""I could imagine why they would believe that. Kinda inferred from "inherent cable velocity""

And your words clearly indicated that you believe the speaker signal arrives at the prop velocity of the wire.  It does not.
And subsequent use of 2nS in geometric calculations is further indication of incomplete understanding.  It is 2 nSec per foot, so the basic prop delay of a 10 foot cable is 20 nanoseconds.  THAT IS ONLY FOR SIGNALS WHICH HAVE THE RELATIONSHIP V = I*Z.  Z being the cable impedance, NOT the load impedance.

They really don't. They need to understand what changes make perceptible improvements in the desirability of their products.

They need to learn how the paramterics affect the sound.  Specifically, for a very small target market where image stability is important.

The end result of everything you are discussing is that the sounds appear with a relative delay (L vs R, 100Hz vs 1000Hz, etc), yes? Wire X has one set of delays and wire Y has another set.

What is the order of magnitude for this delay?

This question means you are either not reading, or not understanding.  Go back in this thread and read slowly please.

I suspect we can find other things that introduce similar amounts of delay, such as driver alignment. That would give us something in real, widespread use we could judge by.

And if we have our head in a vice......

Do not divert by trying to introduce other possibilities like "loose drivers", it is disingenuous..

Assume the speakers don't "suddenly develop" some "problem" as a wire is being swapped.


The bottom line is and always should be...what variables impact the entity that is being produced by the system.
jn

[jneutron]

If I have to use a Zobel with Goertz what should be the component values I should use. Found an interesting article.
 http://www.audioholics.com/reviews/cables/speaker-cable-reviews-faceoff-2/speaker-cable-reviews-faceoff-2-page-3
They recommend using 4.7ohm ,0.1uf for Zobel. Since I am DIYing it I thought I would include it. What type of resistor and capacitor I should go for?

They must recommend the type, no?  Stay away from wirewound and electrolytics.

But honestly, I'd make a multiple zip first, if it doesn't make a diff, same your money.

jn

[kinku]

Thanks John.I thought in the arguments going on you ignored this low Fi man.
I read further and looked at Goertz site ,they actually have a Zobel at an exotic price of course, apparently built using regular components?The link in my last post describes how their zobel was not good in the testing but will work just as fine.
I tried with braiding up two zips and found a difference in sound. I would describe it as instruments and voice seperated out in a nice way(more space) after braiding the zip to HF and some difference in Bass but I would say it is more in my brain since the second person, my friend who listened to could not appreciate a difference in bass.
So I thought about doing this two type wiring for biwiring.
PS:John I PM you some stupid questions. If I am not annoying you please be kind enough to send me a reply.

[jneutron]

Thanks John.I thought in the arguments going on you ignored this low Fi man.
I read further and looked at Goertz site ,they actually have a Zobel at an exotic price of course, apparently built using regular components?The link in my last post describes how their zobel was not good in the testing but will work just as fine.
I tried with braiding up two zips and found a difference in sound. I would describe it as instruments and voice seperated out in a nice way(more space) after braiding the zip to HF and some difference in Bass but I would say it is more in my brain since the second person, my friend who listened to could not appreciate a difference in bass.
So I thought about doing this two type wiring for biwiring.
PS:John I PM you some stupid questions. If I am not annoying you please be kind enough to send me a reply.

It's great that you are trying things.  Remember though, it is very very difficult to be sure that what you are hearing as different is reality.  Nature of the beasts we are is that expectation bias is there to be considered.   Given all the variables in the systems as well as in the human, it is not really possible to analytically guarantee that any of these changes will rise to the level of repeatable audibility.  I can guarantee that the changes are not zero however..

While all the market verbage out there may try to explain some kind of weird science to justify their product, the only differences for speaker cables will be L, R, C, and length.  I've provided the simple math and science to allow the diy'er to experiment with different L and C combinations while not breaking the bank.  If you come up with a combo that you like, just keep it.

jn

ps..I do not recommend using a low impedance cable for the woofer side of a biwire or even for a biamp system.  The cable will look like a capacitor when the woofer unloads at higher frequencies by design, and that may be troubling to an amp.  You'd need a lower frequency zobel in that case, and the delays that the cable mismatch causes at bass are inconsequential as a result of our lack of phase sensitivity at lf. 

[kinku]

Thanks John. I got your PM too. Appreciate your help.

[kinku]

Found something interesting from Vanderstein about biwiring.
http://www.vandersteen.com/pages/Answr7.htm
"All the cables in a bi-wire set must be the same. There is often great temptation to use a wire known for good bass response on the woofer inputs and a different wire known for good treble response on the midrange/tweeter inputs. This will cause the different sonic characteristics of the two wires in the middle frequencies to interfere with the proper blending of the woofer and midrange driver through the crossover point. The consistency of the sound will be severely affected as the different sounding woofer and midrange drivers conflict with each other in the frequency range where our ears are most sensitive to sonic anomalies. The disappointing result is a vague image, a lack of transparency through the midrange and lower treble and a loss of detail and clarity."


From Audioquest 
http://www.audioquest.com/resource_tools/LearningMods/UndrstndgBiWr.pdf

"When BiWiring, the two (bass and treble) cables must either be identical, or
have essentially identical geometries. If the cables have different geometries they will have different capacitance and inductance. Capacitance and inductance are the values used to create a loudspeaker’s low-pass and high-pass filter networks, together making a crossover. Having different  values in the two cables effectively redesigns the crossover…not a good thing! The integrity and coherence of the speaker will be compromised."

And this article  (http://www.synergisticresearch.com/tesla-series/integrated-frequency-transmission-ift-a-better-way-to-bi-wire/ ) for using two different type

"However, If you look at the damping factor that reduces the unwanted signals, you will find that they differ very little, with or without cables (with 5 or 10 meter long cables for example). When using a tube amplifier, the cables (in practice) have no influence at all when dampening the signals from one side of the filter to the other, because the damping factor is too low already in the power amp. The signal will slip through to the other driver, despite the cables. Apart from that, a well designed crossover filter will provide a certain protection against “leaking” inter-modulation, since each half of the filter (the crossover in a two-way system) will damp each half of the frequency range.

Another method of bi-wiring is to run two different cables in parallel, thus giving the amplifier the ability to choose separate cables that are especially suitable for each half of the frequency range. This has been a hallmark of Synergistic Research cable design, going back to our fist Signature speaker wire: The Signature No. 2. If you assume that the signal always takes the path of least resistance, the right path will be chosen automatically"

[Speedskater]

Somehow I would think that the main virtue of bi-wiring is to be able to match the different cable needs of the woofer & tweeter sections. The woofer is most sensitive to end to end resistance and the tweeter is more sensitive to self inductance (or more correctly, end to end high frequency impedance).

[rollo]

It's great that you are trying things.  Remember though, it is very very difficult to be sure that what you are hearing as different is reality.  Nature of the beasts we are is that expectation bias is there to be considered.   Given all the variables in the systems as well as in the human, it is not really possible to analytically guarantee that any of these changes will rise to the level of repeatable audibility.  I can guarantee that the changes are not zero however..

While all the market verbage out there may try to explain some kind of weird science to justify their product, the only differences for speaker cables will be L, R, C, and length.  I've provided the simple math and science to allow the diy'er to experiment with different L and C combinations while not breaking the bank.  If you come up with a combo that you like, just keep it.

jn

ps..I do not recommend using a low impedance cable for the woofer side of a bi wire or even for a bi amp system.  The cable will look like a capacitor when the woofer unloads at higher frequencies by design, and that may be troubling to an amp.  You'd need a lower frequency zobel in that case, and the delays that the cable mismatch causes at bass are inconsequential as a result of our lack of phase sensitivity at lf.

   You make sense to me. If I had the specs of my amps and crossover could a cable be designed to mate with them ? What would one need to know to do that ?
    As a Scientist you think differently than us audio guys. I appreciate and understand your position. WE listen you measure. If the design is proved would you be interested in designing a speaker cable for a lucky guy here if the specs you need are provided ?  It can be a learning experience for all and maybe quell the noise here.
   A pet peeve of mine is that the manf. does not offer specs for cables requirements related to their gear.



charles
   

[jneutron]

Found something interesting from Vanderstein about biwiring.

From Audioquest 

And this article  (http://www.synergisticresearch.com/tesla-series/integrated-frequency-transmission-ift-a-better-way-to-bi-wire/ ) for using two different type
Another method of bi-wiring is to run two different cables in parallel, thus giving the amplifier the ability to choose separate cables that are especially suitable for each half of the frequency range. This has been a hallmark of Synergistic Research cable design, going back to our fist Signature speaker wire: The Signature No. 2. If you assume that the signal always takes the path of least resistance, the right path will be chosen automatically"

So depending on the source, you can find opposites.  That's actually what I find as well.

The basic error of thinking on all their parts is the concept of the "sound characteristic of a wire".  THERE IS NONE.  It is only a distributed L, R, C, and length.

There may be a sonic characteristic of a combination of wire and speaker, but that is caused by the interaction between speaker and wire., They've not yet focussed on that interaction.  Honestly, they haven't because they were told that the wires cannot do that!!  They were told that the wires are too short to even consider t-line effects.  What they were told is incorrect for the specific application.

I work to correct that error in understanding.

jn
 

[jneutron]

   You make sense to me. If I had the specs of my amps and crossover could a cable be designed to mate with them ? What would one need to know to do that ?
    As a Scientist you think differently than us audio guys. I appreciate and understand your position. WE listen you measure.

Actually, I am an engineer.   And, I also have been known to listen in a very rigorous and analytical fashion.

I break listening into two types.  Normal doing something else listening, which is 99% of my life.  And the occasional listening to discover or understand an effect, be it ITD vs IID characteristics of my hearing, toe in/out (polar response) variations of point source location nearfield vs evaluation of source location using two planar waves and zero IID at farfield.

A pet peeve of mine is that the manf. does not offer specs for cables requirements related to their gear.

That's because they don't know.  Nobody does.

The previous post I showed how to make variations in L/C.  The best one can do is try various combinations of cable Z vs speaker and listen.

Eventually perhaps the concept will be widely understood, then you may have to find another thing as a pet peeve.

jn

[kinku]

Thanks John.I did made some twisted speaker cables using 18AWG PTFE wires (total of 4PAIRS for each CHANNEL making it 12AWG).Then I used zip cord to LF and Braided Teflon wire to HF to bi-wire.The sound produced has more clarity, more definition of voices and instrument sounds,spacing between instruments is more clear. But the sound without bi-wiring using only braided Teflon wire as SC has a better imaging.I can hear more sounds with braided cable  in monowire connection,but sounds are crowded together ,little more effort needed to separate sounds out.In monowire connection you can sometimes feel like the singer is near you.In bi-wire combo with zip and PTFE braid I am missing that presence but sounds are well defined and separated. Is any of these matches with an issue of coherence from speakers?

[kinku]

I am finding after few hours of listening that PTFE defenitely makes a difference in sound quality for good. And yes I do not think ,I burned in or anything, it just happened over few hours (4-6) of listening over last week.
I found an explanation  here http://www.empiricalaudio.com/computer-audio/technical-papers/dielectric-absorption-dissipation-factor-and-q
It was expensive compared to DIY using PVC wires from parts express but I am happy with it. Still using Zip cord for LF and braided PTFE 18AWG for HF. this weekend I will switch back  to monowire with PTFE and see which one I like more.Capacitance measured is around 50pF /feet for braided wire,sorry no inductance meter. But according to Jneutron's theory it should be low.The lower capacitance might be from using PTFE insulation with low dielectric constant I assume.(3rd to air and second to cotton)
I am planning to make two more pairs with PTFE for biwiring both speakers to see the difference. Will keep you posted.

[jneutron]

I am finding after few hours of listening that PTFE defenitely makes a difference in sound quality for good. And yes I do not think ,I burned in or anything, it just happened over few hours (4-6) of listening over last week.
I found an explanation  here http://www.empiricalaudio.com/computer-audio/technical-papers/dielectric-absorption-dissipation-factor-and-q
It was expensive compared to DIY using PVC wires from parts express but I am happy with it. Still using Zip cord for LF and braided PTFE 18AWG for HF. this weekend I will switch back  to monowire with PTFE and see which one I like more.Capacitance measured is around 50pF /feet for braided wire,sorry no inductance meter. But according to Jneutron's theory it should be low.The lower capacitance might be from using PTFE insulation with low dielectric constant I assume.(3rd to air and second to cotton)
I am planning to make two more pairs with PTFE for biwiring both speakers to see the difference. Will keep you posted.

The center to center spacing of the wire pair will be determined by the thickness of the insulation.  I find that PVC and PTFE coated wires of the same voltage will have different insulation thicknesses.  Thinner insulation will give a lower cable characteristic impedance.  So it is very possible that it is not dielectric absorbtion which is the cause.

Your cable inductances should be rather close to:

L(in nH per foot) = (1034*4)/C (in pf per foot)  edit:  the more conductors you use in the braid the closer to 2.7 you will get, not the "4" I chose in the (1034 *4).

Never forget that your assertions of sound differences will not be accepted as proof of anything unless you do some kind of dbt stuff.  Expectation bias and all...

In the end, while I have provided a clear scientific basis for differences, the audibility question is still up in the air.  If you like what you hear and attribute it to the cable changes, great.. I cannot state one way or the other regarding what you perceive..

But ya know the "science guys" will still rag on ya, right?

jn

[rich2ch]

jn,

Your insight on the insulation thickness is an interesting insight. Somehow I am lost on the significance of 2.7.

[kinku]

John,it is hard.There is science everywhere you have to find it.. So using PTFE does not reduce the capacitance too much I guess ,except if it is lower in thickness than PVC.
Like you said it might be in my brain but..... I have a "non audiophile" friend who starts talking something else, the moment I invite him to listen to a track..I simply can not make him listen to anything. Last week he visited me and listened to a whole track(by accident , was in background then he stopped talking and started singing with it) and said "something is good about it from all the previous times I have been here". He does not now any of these stuff and do not even know what audio quality is.
I started listening in triode mode on my Cayin A70-T ,which I never used to do before.Before I used to always switch to ultra-linear mode.
What is DBT?