Are there any constants in speaker wire designs?

"Why is "strand jumping" bad?"

Strand jumping is related to skin effect that forces current to jump constantly to outside of thick speaker cable (where resistance is lower at higher frequencies). Copper impurities reside on the surface of each strand. Copper oxide is a semiconductor.

Isolating strands prevents jumping but skin effect still exists because strands are still in each others magnetic field (surface is increased though). Here comes helical winding on hollow tube (used by many companies like AQ or AZ) making each strand to be only in magnetic field of adjacent strands. Some companies use flat-woven design or flat copper tape to achieve the same. Flat copper tape is often used in crossovers inductors (for the same reason).

Don't ask me how significant skin effect is because I don't know. From electrical point of view it most likely doesn't have any effect but I don't pretend to know more than cable companies. Solid wire with limited gauge might be an easy compromise. Since skin effect starts at gauge 18 for copper at audio frequencies (20kHz) it is probably safe to assume that even 14 gauge solid wire (like very popular AQ type4) will do job nicely. It has a little more resistance but inductor in a series with the woofer has most likely as much as 0.1 ohm anyway.

On the top of these exotic geometries purity (and type) of metal might play a role as well as dielectric used that changes with the price of the cable with foam Teflon being the best.

My take on this: If it is all placebo effect what is wrong with it as long as it works? You paid for something that sounds better to you whatever the reason. On the other hand I installed once brand new AQ Indigo speaker cable and had for the first hour very muffled sound that changed for next few hours to overly bright to become smooth and balanced within few days. At the same time I read at this forum posts stating that there is no such thing as cable breaking.

Irvrobinson - I can make argument as well, that if you want to believe that top cables don't sound any better than cheap lamp cord - they won't (negative placebo effect).

Long time ago when I had thick stranded Monster speaker cable and amp with tone control I had treble always set at +2dB. After change to AQ Indigo I had to move treble to 0dB position. Nothing else changed.

I agree that looking at dB scale skin effect is not important in audio but remember that we are able to distinguish sounds of different violin brands so subtle that difference cannot be even measured. 0.2dB might be nothing in terms of volume but can have effect when harmonics are summed differently (frequency smearing). Cable companies not only know more but also design very similar cables (came to similar conclusions).

You cannot possibly explain different sound of copper and silver but if you scan this and other cable forums you'll find that 90% of people found silver to be brighter/faster sounding. AZ Absolute IC that I use is silver with 1% copper. Why would they do that (adding copper), if it doesn't make any difference. It requires making special alloys. Important here is that it is not a marketing ploy since they don't advertise this and I had really hard time to dig this out.

My AZ Satori speaker cable is a class above previous AQ Indigo (transparency, smoothness, speed) but has one characteristic absolutely necessary with lean sounding class D amp - pronounced lower midrange (try to explain this in terms of RLC). Indigo sounds, in comparison, thin and flat. Satori adds fullness and chestiness to male voices. It is pretty big difference that even my wife noticed (sorry honey). You could say again, that it is placebo effect but I bought this cable because somebody else complained on the cable forum about this midrange fullness and sold the cable.

As for differences between cables that are "almost certainly imagined" - my friend says the same about amplifiers and CD players.

Mcelio - AFAIK Nordost cables offer specific "house sound". Let just say that if you're looking to add warmth to the sound or suppress sibilance Nordost isn't the one. On the opposite side is Cardas that is warm sounding but does not have transparency of Nordost. Try both if you hear the difference. My Monster speaker wires (thick stranded in clear insulation) were suppressing treble - Nordost should add treble and extension.

Can you borrow cables from the the local audio store for a few days - just to see if you can hear the difference? Ideal would be to borrow completely different families like Cardas and Nordost.

Mjordans - I was talking about general opinion on the forums and in reviews.

In AVGuide review: http://www.avguide.com/review/nordost-tyr-cable I found this statement:

"That Nordost have evolved a distinctive house sound is indisputable. Fast, crisp and loaded with so much treble energy they can make other cables sound distinctly rolled-off, they are not for everybody."

Brightness is often blamed on cables when it really comes from SS gear or speakers but you have to agree with me that "Lean" is the most common word used to describe Nordost cables.

"You are correct about skin effect. Skin effect is a phenomenon that you tend to see at microwave frequencies."

This is incorrect. At microwave frequencies skin depth is in order of um. At audio frequency of 20kHz largest copper wire that has still the same resistance for DC as AC is gauge 18. Please check skin depth calculator here:

http://daycounter.com/Calculators/SkinEffect/Skin-Effect-Calculator.phtml

Skin effect is very pronounced at video frequencies. That's why cables are made of cheap metal silver plated (signal travels on the surface).

Skin effect allows for shielding. Interconnect for instance cannot be possibly protected from electromagnetic pickup of high frequency signals by non-magnetic shield. What really happens is that shield passes these high frequencies and they are induced in the cable, but because of skin effect they travel on the outside of the cable - shield. Internally field is zero as long as wire is symmetrical. Without skin effect aluminum foil or copper braid would not shield higher frequencies (would protect only for capacitive pick-up). Shielding is very complicated. Shield is carrying externally induced high frequencies on its outside while at the same time common mode high frequency signal noise travels on the inside of the same shield. At lower frequencies shield does not protect at all but wire is to short to become effective antenna (starts at 1/10 of wavelength)

Audio cables are much more complicated than just RLC. If I remember correctly Muralman1 uses in his design cable different metals for signal and Ground wires. You cannot explain in terms of RLC how different metals change the sound.

Paperw8 - according to mentioned skin depth calculator 20 mils corresponds to gage 18. Skin effect is therefore not existent in interconnects but might with speaker cables. Using thick wire lowers resistance but also inductance. The same happens with stranded wires. Isolating strands doesn't help them being in each other magnetic field (doesn't reduce overall skin effect) but placing strands on the hollow core or flat woven pattern does.

I understand that you are sceptical about skin effect in audio (as I am) since we need couple of dB to notice volume change but on the other hand fraction of dB on the tone control can be perceived.

All cable companies go toward similar solution like flat cables (Nordost) or hollow tube cables (AQ, AZ). I tend to trust them and suspect that they don't do this for marketing purpose alone since most of customers have no idea what skin effect is. I can hear specific difference between speaker cables while other tell me I must be self hypnotized and that cheap Home Depot wire is good enough.

I don't know how to measure focus or soundstage depth or width but it exists and is affected by something. Can this something be simply measured by relation between R, L and C.
Can we say that all speaker cables that have exactly same RLC will have exactly same sound (focus, soundstaging, etc.)? What about R,L or C vs frequency - it might be complex relationship?

Magfan,

Yes, RLC is just gross description. There might be even variables that we don't know yet. They claimed in 70's that new SS amps have to sound better than tube amps because they have wider bandwidth and much lower THD and IMD. They just didn't know about transient intermodulation (TIM) that was discovered in 70's. I know that wire is just a wire but shielding for instance (as I mentioned before) can be extremely complicated.

Mjordans,

I had a few AQ ICs and can say that Viper has better low frequency extension that Ruby. I cannot imagine how RLC can be used to describe this. Not likely placebo effect since I could tell easily which cable was installed and did not read any opinions/reviews. In addition there are many IC cables reviews where they mention bass extension. Midbass was about the same but Viper had better bass definition. How we can posssibly explain tighter bass in RLC? Capacitance or inductance values are completely irrelevant at these frequencies. My current IC has about 7pF/30nH - not significant at any audio frequency. What makes this cable to sound different from other cables of similar, not significant RLC. Shielding with non-magnetic shield works against EMI, as I described before, because of skin effect. But this is only if cable is very symmetrical (equivalent field inside is zero) and only at higher frequencies. There will be some frequencies at which skin depth will be too deep to contain induced interference to shield alone while cable will be long enough to be some antenna. Antenna works effectively at 1/4 wavelength and stops working perhaps below 1/10 but there will be still some pickup even at shorter cables. Single MHz frequencies can perhaps do that (bypass the shielding and be induced). Maybe they tend to do something to modulate output driver and that's why cables might be so system dependent.