T, I think it was Jean Hiraga in L'Audiophile magazine in the mid to late '70's, who wrote the first interesting article on cables. I can't find it now, unfortunately. There was someone in the USA named Fulton, who made interesting cables about the same time. The so called Fulton cables were considered a break-through at the time. I personally do not use zip cord anymore, but I must admit, things got out of proportion for a decade or two. YBA was also into cables in the past, and Dr Vandenhul as well as Dr Hawksford wrote about their researches on the subject. I know the them all and will vouch for their seriousness in pursuing this matter.
You might want to catch up on some of the research about how human minds work. An excellent introduction would be Danial Kahneman's, Thinking Fast and Slow. Highly recommended. National Science Foundation book of the the year, NYT bestseller, etc.
Just for JN,
https://www.eeweb.com/tools/wire-inductance
Uses a formula to get about 1.3 uH per meter of a typical single conductor wire, a wee bit higher than I would expect! That would limit a 50M wire to 20,000 Hz into an 8 ohm resistive load.
Now as most if us require 2 conductors that would limit cable lengths for full range audio with losses below the perceptual limit of many of use to less than 10M of cable.
As I need to have a chat with some folks in a few weeks about large scale sound system issues they are unaware of, I will be measuring some actual cables of the type allowed for such use.
https://www.eeweb.com/tools/wire-inductance
Uses a formula to get about 1.3 uH per meter of a typical single conductor wire, a wee bit higher than I would expect! That would limit a 50M wire to 20,000 Hz into an 8 ohm resistive load.
Now as most if us require 2 conductors that would limit cable lengths for full range audio with losses below the perceptual limit of many of use to less than 10M of cable.
As I need to have a chat with some folks in a few weeks about large scale sound system issues they are unaware of, I will be measuring some actual cables of the type allowed for such use.
Pursuit of maximum productivity is a serious matter, you scratch my back I'll scratch yours, it's blatant amongst the purveyors of financially lucrative FUD on this site for example.
In the same time frame, there was also a guy called JC in Berkeley, CA, who devised a way to measure the rise time of speaker cables; this has a fairly good correlation with their sound.
The 1st pict is a "star quad" configuration lifted from the telephony guys who used it to fight linear inductance in their lines. Peter Moncrieff talked about it and Pioneer marketed it as a high-end audio cable. I was pretty happy with it until the day I was given some Kimber...
Attachments
2 closely spaced parallel wires have lower inductance than 1 single wire.
Parallel Wire Inductance Calculator - Electrical Engineering & Electronics Tools
A few of the Hi End enthusiasts I know years ago spent decent money on fairly esoteric cables but everyone wised up and realized that they don't so much sound better or worse, just mostly different and more suitable for a particular system.
These days everyone just makes their own. 50 bucks of raw materials from Parts connexion, your local hardware store etc and you have a cable making kit that will produce many metres of whatever you like.
Even stuff like UPOCC is available for pretty cheap and you can decide if it's voodoo or not over a beer with friends.
T
I have read that. Nothing new from that one. Not that I have read about it in another book, no.
As others have pointed out, the real calculation requires a return current path. As such, a single conductor calculation is of no use for us, and the geometry of the current loop is what dominates.
Twin conductors start about 150 nH per foot with no insulation spacing. I use 200 nH per foot as a generic rule of thumb.
That calculator gives slightly different results from terman w/r to parallel wires with thin insulation, but not too far off. Terman calcs were within 4% of actual measurements I did a while ago (maybe 15 years ago) for various wires from twisted 24 PVC to #10 Teflon in the frequency range of 20hz to 50K.
Of course, every time I try to measure a single wire, the meter display blinks, they insist on a current return path..
Jn
I am also confident that they were serious. However, there is a vast distinction between "serious" and correct. Hawksford at least published the entire derivation and test method, which demonstrated how serious he was. It was through that publishing that we could find his errors.
That is how it should be..I am glad he published all.
Jn
I am again and again surprised of basic ignorance and lack of basic knowledge of the members that seem to be quite highly regarded in the audio field. Like in this last case, when someone considers a single wire inductance and then deduces that a speaker twin wire would have higher inductance than a single wire. Similar as ignorance of Ohms law or Kirchhoff's laws. However, subtle effects of non-existent phenomena seem to be very well understood and are considered as open-minded thinking.
I agree with Terry about making ones own cables. I bought a 50 metre roll of 5mm^2 twin cable (70 strand IIRC) that can take serious amps. some decent banana plugs or spades, a bit of heat shrink and you are good to go.
Again, at dealer events, my probably 50A capable cables are called out, and replaced with all sorts of magical wires that apparently make a huge difference that I have as yet been unable to detect. Of course, dealers make money on cables so I understand the commercial motivation but don't accept any technical motivation for their approach, so I gracefully step back.
Like the £300 grounding box that made not one jot of difference to the hum caused by a guy who decided to **** the PSU on a top of the range Oppo and charge customers another 2 grand over the Oppo street price claiming it was a dCS killer.
The vagaries of audio . . .
Again, at dealer events, my probably 50A capable cables are called out, and replaced with all sorts of magical wires that apparently make a huge difference that I have as yet been unable to detect. Of course, dealers make money on cables so I understand the commercial motivation but don't accept any technical motivation for their approach, so I gracefully step back.
Like the £300 grounding box that made not one jot of difference to the hum caused by a guy who decided to **** the PSU on a top of the range Oppo and charge customers another 2 grand over the Oppo street price claiming it was a dCS killer.
The vagaries of audio . . .
JN I believe understood the fun I was poking at the single wire formula. If you run the numbers for a cable I think you will get the same limits I showed.
In measurements of cables on spools the coupling even with twisted pairs results in inductances that would indicate loudspeakers would not work in large installations.
Next we could consider other ways to reduce the effect.
Turns out there might be a reason the early movie theater loudspeakers used 16 ohm compression drivers for cable runs of say 75M.
Equalizers weren't around then. In a large scale system boosts of 20 dB at 8,000 Hz. are common. Some of that is cable, some atmospheric absorption and an interesting bit is cable coupling.
On my opinion, it is not "non-existent phenomena" in the matter of cables. It is more the abusive generalisation of existing phenomena specific to a particular situation.
If you are in a high end store, comfortably sitten in an harchair for a comparing session of cables listenings, with all the incense of this ceremony, you will feel differences. It is not a miracle, they exists.
Why ?
Nothing strange: you are listening to speakers. They are resonating devices, and their resonances are dumped by the amp internal resistance. More or less, depending of the serial cable impedance.
You are feeding a load witch have usually a very tortured impedance curve. Adding a resistance (the one of the cable) in serial, you will change slightly the response curve.
Not to forget that the capacitance of the cable will more or less change the phase shift at HF. The amount of this phase shift depends of the internal impedance of the amp as well, And any change of overshoots of the square waves will depend of its stability margin.
Now, the seller will try to make you believe that it is some kind of "Character" of the cable itself that makes a difference. And he will direct you, of course, to the most expensive.
Back to home, you can have a different result, if your amps and speakers are not identical, but, still convinced, you will, of course, confirm your choice: How the "character" of something could be changed ? And how could-you be wrong, having listened with such an effort and such care, all along with your "expert" seller ? ;-)
Now, if, like me, you flatten the impedance curve of your speakers with RC and RLC parallel networks, you will find that the tonal differences between two cables, that were easy to discriminate without, suddenly disappeared. And, if the resistance of the two cables are identical, the bass rendering as well.
NB: When I say "you", it is not addressed to you, PMA. OF course, you know-it.
All this is resumed in this amusing sentence of Peter J. Walker about his opinion on cables sound qualities : "I tend to prefer the ones that conduct electricity."
Now, if you are an average customer, with no way to change anything in those expensive closed boxes that are your amplifiers and speakers, the only way you have to improve the rendering of your set-up ... is to change the cables ...
Like taking aspirin when we have a headache.
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What boggles me is...I cannot think of any reason why a "single wire--no return path" inductance calculator would exist. While it's a great theoretical physics final exam question for a three dimensional integration of stored mag field energy on a segment of current in space, I see no practical use. I work around particle beam machines and still see no use for that. Even the particle beam machines consider the system as a coax with return currents along the walls (or shield for us).
Maybe for a particle beam weapon perhaps?
Jn
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