Stranded vs singal core conductors and skin effect


Yea, Yea, I did a search. I did find similar topics, but I still don't know which solution is preferable. Many mega-buck cables utilize solid core. Is solid core a better solution (conductor, etc.)? Isn't it the geometry (twisting, braiding, etc.) that addresses the skin effect issues? Are there other scientific reasons for utilizing stranded wire vs singal core? I am really considering making some DIY speaker cables. If for no other reason, than just for kicks - sounds kind of fun. I have read up on so many different theories. I realize that inductance and resistance are extremely important factors, as well as capitance, and for whatever reason, it must be a challange to design a cable with extreamly low measurments in all three categories?? I don't really fully understand why. HOLD ON - I don't want a complete lesson here. I'm just seeking some input from the engineering-minded or the knowledgeable DIY community as to which type of wire offers the best conductivity (and other factors??) for designing a DIY speaker cable. Additionally, which geometry is the preferred method?
2chnlben
I am an engineer. I would not worry too much - either stranded or solid core will work fine. Skin effect is a minor detail - it may affect what you hear above 15 KHz by as much as a mere 0.1 decibel in a worst case - that is assuming you have ears like a bat. If you are like me then it really doesn't deserve the worry.

On the other hand, although solid core is cheap it is also stiff and may give you more trouble with contacts (if you ever move your speaker or amp to clean then a flexible braided wire is much more sensible)

Geometry is best served with +/- speaker wires close together - this lowers inductance - but once again the effect on group delay (speed at which frequencies travel) is in the range of 100 nanoseconds so no need to panic - whatever exotic geometry excites you the most - take your pick - differences are extremely small. 100 nanoseconds is equivalent to 0.1 of a millionth of a second. This is small even if one hundred sounds big (in nanoseconds). I mean can you actually sit with your head and speakers positioned to the precision of one thousandth of an inch (much less than a human hair)- if you can then you should definitely start to worry about it as that is the kind of distance sound will travel in 100 nanoseconds.

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Shadorne:
Thank you. This is exactly the type of input/advise I was seeking. It's so much more enjoyable, and much less of a hassle, to acquire information this way rather than having to sort through all the clutter via a web search. I realize now that the geometry of a cable design deals with the issues of inductance, and size/diameter is related to skin effect and resistance. The more I read up on the matter, the more I think I'll just look for a good assembled cable. It's not as if I have allot of time on my hands, although, it sounds intriguing. I've been reading about some DIY recipes that are "said" to better some really heavy hitters. As an audio enthusiast with an engineering background, have you ever experimented with DIY cabling??
I done a lot of DIY, including a linestage, DAC, speakers and acoustics but good, inexpensive speaker cable is too easily available for me to bother wasting my time. I just look for a sensible design with teflon insulation.
As an audio enthusiast with an engineering background, have you ever experimented with DIY cabling??

I have tried 12 AWG 16 AWG - can't say as I can hear a difference but I tend to try to choose components in a rather specific way;

=> speakers that are an easy load (not 4 Ohm and no nasty dips )

= amps whose output is not sensitve to load variations.

...perhaps this explains my experience perhaps I just have tin ears or I blindly accept all to readily what was taught to me in school. Whatever it is, my experience does not match what others find. So youu have to make up your own mind.
Don't be surprised if, after experimentation and auditioning new cables, you wonder if you improved anything compared to your Kimber 4tc. Like Shadorne said, if your speakers are an easy load and your amp has no unusual quirks, getting spendy on speaker cable might yield you poor returns on dollars spent. Kimber 4tc is no slouch.
Thanks for the "sound" advice. You know, I think I've simply been putting off the DIY project that really needs to be addressed in my system - room treatments. I've got the proverbial itch going as of late and I have been playing around with tweaks, but ignoring the acoustic treatments. Like so many, I want to maintain a nice "livable" area and at the same time, a good sounding area, without have one infringe upon the other. Besides, I’m having a darned hard time finding Owens Corning 700 series products?? Years ago, when I built a dedicated sound room for my first wife (it was for me at the time, but she ended up with it….because it was IN the HOUSE!) I was able to purchase it locally. Can’t find a local supplier now?? Boy, how I digress…this is supposed to be about cables. I think I’m past that now. Thanks!
Now you're talkin'. Room treatments potentially offer an upgrade of considerable impact for not much dinero if you go the DIY route. Acoustimac.com and other internet outlets are where you need to look for DIY supplies. After making four DIY bass traps, I couldn't believe how much improvement was realized for a weekends work and minimal cash outlay.
There`s a lot of legends around this theme. One is that thicker cores gives skin-effect, that`s just a farytale as long as we talk about audio frequenses.
In princip there should be no multicore anywhere in a system if you want the ultimate. Not only do the signal run blindly between the different conductors and by that generating a lot of distortion/energy loss, houndreds og hairthin conductors do not work as well as onr thick even if it does teoreticly.

I`ve done a lot of research on this, in any level from ic`s to powercords. Not any solid conductor will do, the best stranded might outperform some solids. Flat/foil is not optimal, even if the legend tells so.
The whole powercircuit from trafo secondarys and all the way into the speakers voice-coil should are were sensitive to resistance and should be done in heavy gauge solid core. One of my best uppgrades was a set of custom-built trafor for my poweramp, completed with a set of solid core powercords.
"I am an engineer." So am I.

Don't ever let anyone hit you over the head with college degrees, experience, or whatever. In other words, you don't have to be a cook to know what things taste like. Try things out, and come to your own conclusions. Regardless of how things measure, I've learned enough to know that my ears are the most important piece of equipment I will likely ever come across. If you hear the difference, it is real.
Trelja, So am I, an engineer, that is and an amateur cook. About tasting, it is easy to get people to think that there is a difference in the taste of different salts and inevitably those people do 'taste' a difference, when, unless the salt has been deliberatly doctored, there is no difference. So careful with analogies.

I have also learned that my ears-mind are also easily fooled and therefore not always reliable for detecting differences even when they are real, nevermind when they aren't real.

I do understand, however, the expression, 'perception is reality' and perhaps that that is what you mean.

Respectfully, Bob P.
Bob, yes, that is what I meant.

But, different salts (or, spices) do taste different in the same way that different cables sound different.

No one really questions subjectivist opinions when it comes to food, wine, wristwatches, clothes, shoes, furniture, etc. When I say I like Coke better than Pepsi, no one has ever really had a big problem with it. I've never had to justify it beyond saying it's that battery acid taste that does it for me, even to those who preferred Pepsi (or RC Cola) - and, even having to say that much is rare. The same acceptance doesn't exist if I say I like high-end audio component A better than component B. Somehow, the latter position MUST be justified empirically. For whatever reason (a lot of which is ego) these matters are such a big deal in audio. Things must be measured; the resulting specs then shoved down people's throats in order to justify or denigrate.

Bud Fried's famous anecdote of the island's clock tower comes to mind in terms of the dangers of depending on specs, and how foolish we are on relying on equipment and their resultant measurements that have not been fully developed at this point in our development as scientists and engineers.

Music is supposed to be fun. Objectifying audio, which is a relatively impossible feat (at least, today) in my opinion, tends to turn things into spitting contests, which for me is the antithesis of fun or what a hobby should be about.
My point, however, Trelja, was that all salt tastes the same, but people do think that they detect different tastes, because someone has convinced them that salt from the sea is different than salt from the inland salt caverns. Theoretically, perhaps, there is a difference, but practically, the level of salinity is so high that one could not taste the difference, if indeed there is one. same with the stranded skin effect on the sound of cables. Yes in theory, but no in practice.

Bob P.
Cables are pure simple physics, no big deal. Thick solid are the optimal solution, but every other configuration also gives a signal, it just ain`t that pure and powerful anylonger.
Skin effect is not an issue for audio freqs = I started out in electronics as a teenager building a Heathkit 101 ham radio, worked as an electronics tech in the US Navy, earned a BSEE after return to civilian life and spent two decades working in the field. Skin effect is a big issue at radio freqs but the effect on low freqs (and audio comprises relatively low freqs) just is not an issue. As with a lot of snake oil, there is always a kernal of truth - the push to sell cables based on ideas like skin effect is a classic in this regard - take some scientific principle and then expand its reach - it is not whether skin effect has affects audio freqs- rather it is the magnitude of the effect that matters. The only thing that really matters as far as speaker wire (assuming that your runs are relatively short (50 ft or less) - is the awg - small awg - big wire - low resistance - less IIR losses. stranded vs solid - the stranded will be more flexible.
Musicnoise,

I could not agree more with your statement above. We live in a highly unethical modern world of sophisticated snake oil (couched in science). Audio cables are just a tiny microcosm of the problem. You have TV adds now (that governments allow) which suggest what ailments you may suffer from and what drugs you should ask your doctor to prescribe you. Worse you have Al Gore running around like Henny Penny telling everybody the sky is falling down with the snake oil of Global Warming. The science/data behind many modern ridiculous hyperbole is actually unfounded - all extrapolated from faulty statistical analysis/testimonials and a few kernels of truth, such as that CO2 is what atmospheric physicists would call a green house gas.
try a 2mm magnet wire that resemble anti-cable. there is few success in this method. you might just lose few buck if its not working. just my 2 cents
"But, different salts (or, spices) do taste different in the same way that different cables sound different."

Bob's right I'm afraid; salt is salt. It's a sodium chloride crystal and if pure will taste the same regardless of what brand it is. However, they can taste different due to additives or impurities. Sea salt can contain other minerals which alter the flavor.

Using that analogy, cables can sound different when made from different metals (eg copper, silver, blends etc), but comparing one 99.99% OFC copper cable to another is unlikely to yield much difference, provided the AWG suits the length of cable run.

And I'm not an engineer!
Sometimes I wonder if even keeping the DC resistance low by using large wire is important. When I first made up some biwire cables for my Maggies I used small #24 wire for the tweeter. The tweeter connection led directly to a 1.5 ohm padding resistor. I put the ohms in the cable and eliminated the resistor. Results were fine.
Sometimes I wonder if even keeping the DC resistance low by using large wire is important.

I agree it is relative. If you have a low impedance load then it starts to become a small factor. With well designed speakers and short runs and an appropriate amp - it is really no big deal at all. That this speaker cable issue continues to come up as often as it does suggests a great deal of insecurity over audio systems in general. Is it perfect? Am I missing something? Is something damaging my sound? Might gold or silver be better?

Like the nonsense spam email directed specifically at males, "How to better satisfy your wife/GF". Also obviously designed to play on male insecurities...