Why are we going 300 or more directions?


Funny, if you design a hi-speed coaxial cable, the fundamental design is the same. I do mean the same. Physics have honed the basic construct to the same physical design no matter who makes it.

Yes, conductor and shield materials will change some based on the frequency range, but not the design. If you change the basic design, you get worse performance, and not just differentiation (unless worse is your differentiation).

Then we have audio cables. True, audio exist in a frequency range where stuff does change with respect to frequency (impedance drops markedly as frequency is swept from 20 to 20 kHz) but this still doesn't allow willy-nilly designs from A to Z to hold the best electrical ideal.

If there are X number of speaker cable makers, only a small few can be the most ideally right according to physics for audio transmission. What we have is so much differentiation that it is almost humorous.

If "we", as in speaker cable designers, all got in a big room with the door locked and could not be let out till we balanced the design to best effect...what would that cable look like? Why?

Go to any web site and you can't get one-third of the way through before vendors allow misconception to be believed (references to velocity of propagation for instance) that are meaningless in their feint of hand or simply unprovable as to their effect...simply fear you don't have it. For instance, high velocity of propagation allows you to simply lower capacitance, the speed is there, but irrelevant at audio and cable lengths that you use. The signal travels too fast to matter. Signal delay is in the 16ns range in ten feet. Yes, that's 16 trillionths of a second. It's the capacitance folks, not the velocity that you engineer to. But velocity "sounds" exciting.

Audio cable over the years should be under CONSOLIDATION of principals and getting MORE like one another, not less so. I don't see a glimmer of this at all.

The laws of physics say there is a most correct way to move a electrical signal, like it or not. Electrical and magnetic fields have no marketing departments, they just want to move from A to B with as little energy lost as possible. You have to reach a best balance of variables. Yes, audio is a balance as it is in an electromagnetic transition region I mentioned earlier, but it STILL adheres to fundamental principals that can be weighed in importance and designed around.

A good cable does not need "trust me" engineering. An no, the same R, L and C in two cables don't make them the same. We all know it isn't that simple. BUT, the attributes (skin effect and phase responses) that DO make those same R, L and C cables different aren't magic, either.

I've listened to MANY cables this past six months, and it no longer amazes me which ones sound the best. I look at the several tenets that shape the sound and the designs that do this the most faithfully always come out on top.

DESIGN is first. Management of R, L, C, Skin effect and phase. Anyone cam stuff expensive material in a cable, few can DESIGN the right electrical relationships inside the cable. Why be stuck with excessive capacitance (over 50 pF/foot) to get low inductance (less than 0.100 uH/foot) when it's NOT required, for instance. A good design can give you BOTH!

MATERIALS are a distant second to sound quality. They contribute maybe 2 tenths of the total sonic equation in a quality design and ZERO in a bad design. A good design with standard tough pitch copper will exceed a bad design with single crystal cryogenic OFC silver-plated copper. You can't fake good cable design and the physics say so. Anyone can buy materials, so few can do design.

Being different to be different isn't a positive attribute in audio cables. Except for all but ONE ideal design it’s just a mistake.

I've listened to the same cables with dynamic speakers and electrostatic speakers, and the SAME cables always come through with the same characteristics. Good stays good. True, the magnitude of character is different, but the order hasn't moved.

I'm not real proud of the cable industry in general. True transmission accomplishments should reach common ground on explainable principals and that SHOULD drive DESIGN to a better ideal. But, we people do have emotions and marketing.

What do I look for in a speaker cable?

1.0 Low capacitance. Less than 50 Pf / foot to avoid amplifier issues and phase response from first order filter effects where the phase is changing well before the high-end is attenuated. The voltage rise time issue isn't the main reason low capacitance is nice, it's that low capacitance removes the phase shift to inaudible frequencies and doesn't kill amplifiers.

2.0 Low inductance as we are moving lots of CURRENT to speakers. Less than 0.1UH /foot is what you want to see. Good designs can do low cap and low inductance, both.

3.0 Low resistance to avoid the speaker cables influencing the speakers response. The cable becomes part of the crossover network if the resistance is too high. For ten-foot runs, look for 14 AWG to maybe 10 AWG. Bigger isn't better as it makes skin depth management issue too hard to well, manage.

4.0 Audio has a skin depth of 18-mils. This is where the current in the wire center is 37% of that on the surface. The current gradients can be vastly improved with smaller wire (current closer to the same everywhere). How small? My general rule is about a 24 AWG wire as this drop the current gradient differential across the audio spectrum to a value much less than 37%. Yes, that's several wires. Don't go overboard, though. Too much wire is a capacitance nightmare. Get the resistance job done then STOP at that wire count.

5.0 Conductor management. Yes, point four above says more than one wire, many more! And, if you use 24 AWG wire for skin depth management, it can be SOLID to avoid long term oxidation issues. I've taken apart some old wires and it can look pretty bad inside! Each wire needs it's own insulation.

6.0 Symmetrical design. Both legs are identical in physical designs allows much easier management of electricals.

7.0 Proper B and E field management is indirectly taken care of by inductance and capacitance values. The physics say you did it, or you didn't. BUT, you can design in passive RF cancellation if you use a good design, too. Low inductance says that emissions will be low, however, as less of the energy is generating an electric and magnetic field around the wire, thus limiting EMI / RFI emissions.

8.0 Copper quality is finally on the list. It doesn't matter without one to seven! The smaller the wires (infinitely small), the LESS the silver plate will warp the sonics. If the current density is the SAME at all frequencies, then all frequencies see the same benefit. If a wire is infinitely big than the high frequencies will see the majority of the benefit. 20 Hz and 20kHz are at the same current density on the wire surface. But, the gradient difference is too small to matter with 24 AWG wires. If you want silver, let the silver benefit everywhere!

9.0 Dielectrics. Dead last. Why? Because capacitance is driven by your dielectric. If you have the low cap, you have the right dielectric for the design. You HEAR the capacitance and NOT the dielectric per say. True, Teflon allows a lower capacitance for the same distance between wires, thus making lower capacitance. But, if you FOAM HDPE from 2.25 down to 2.1 dielectric constant, it can meet the same cap at the same wall and sound just as good. Careful though, it is now more fragile! It's a trade-off in durability, not sound quality. Teflon isn’t magic. It is expensive.

10.0 This is not last per say as it is CHOICE in design. I do not like fragile cables laying on the floor to be stepped on. Some do. A good cable design should be durable enough to take that late night trip to the TV set with the light low, and then step on your cable by accident. The cable should be user friendly.

Everything above can be calculated by known physics equations with the exception of copper quality on sound. I'll have to hear this on two IDENTICAL cables except wire quality. But, why would a vendor allow you to do that when they can scare you into a more expensive copper? I'll be glad to pony-up if I'm allowed to make the judgement for myself. Or, let be buy it at a reasonable price!
rower30
Oops, somebody forgot wire directionality. I forget in which electronics textbook that is discussed. :-)
No, didn't forget directionality it at all, it doesn't matter. Audio signals are not truly symmetrical or balanced (plus to minus signal don't subtract to zero) as impulse noises are more positive amplitude than the negative decay. Look at a piano or drum strike, for instance. Yep, more stuff on the positive side than the negative side. But this is no reason to think the "positive side" needs help.

The waveform is alternating current and travels BOTH directions with respect to polarity. What half of the waveform do you want to be biased with the copper "grain" structure? If this was a DC signal, rubbing against the copper grain structure the wrong way may be a fun FUD argument. But since audio cables aren't a cat and get pissed when rubbed the wrong way and are AC in nature, this concept of current "direction" when it has reversal changes to even play music is rather odd.

I already discussed polarity reversal timing (fast as the dickens) in the dielectric relative to single directional changes. How on earth could AC signals even be transmitted if the dielectric were "slow"? Coaxial cables transmit in the 6 Gig frequency range all day with out directionality just fine, thank you. And, their dielectrics don't need help...

DC dielectric bias systems are also perplexing. DC bias systems further tell you that the signal could care less about directionality and polarity as a DC bias system theoretically makes it HARDER to polarize in the opposite direction of the bias. All good dielectrics polarize so fast that a DC impediment doesn't audibly affect the sound, just your pocket book. Why so much concern for the BIAS in the ONE direction only? And no, a dielectric doesn't take seconds, minutes, hours or days to polarize. It takes 10 to the minus fourteen seconds. Do they wander around after power is removed? Yes. Do they snap back into control IMMEDIATELY when a signal is applied? Yes. If you listen to music at the 10 to the tenth power in frequency...be worried, very worried, as the polarization can now not keep up. So how does a DC battery bias system add speed to an audio signal dielectric and to both polarities, not just one?

But if you must, mark your cable and add an arrow to make you feel good along with a battery and heavens don’t put the battery in the wrong direction! :)

I'm not against REAL design metrics that is repeatable and you can design around. To jump to RF wave-guide signals and force an issue at audio is simply misguided. Audio cables are hard enough without using physics the wrong way.

All the attributes I discussed are measurable at audio, and the improvements to them rational in a good design. Diectionality, DC bias and many others are not. But if you want to add nonesense to cables, why not add it to a cable that at least is designed right up to the arrows and battery installation steps? Are we tossing out what we can measure and replacing it with what we can't? Yep, we see pages of FUD "data" (differentiation)with no mention of the compliance to the physical basics. If a cable meets the basics, at least the FUD stuff didn't hurt the sound, just your pocket book.
Rower30: your original post & further "articles" are very interesting and, if i may say so, a significant contribution to the community.
I do of course agree with your basic premise but never have managed to put the matter in the same clear terms:)

Not surprisingly and for just as unsurprising identical reasons, the branded cables I use (I also use diy) are the same...
(And yes, the nuisance of "avoiding" that annoying HF phase shift makes me wish I had specialised in low voltage applications in my youth...)

A while ago I was trying to find the "optimal" gauge for a simple IC consisting of two conductors running parallel at ~1.5" apart, 2ft length, unshielded, using single strands of copper wire of course.
Not having the right equip to measure, I had to use my system & concluded that 24awg offered the best frequency extension, but lower gauges more "dynamics" (i.e. 24 is over the R turning point it seems). As I use a transformer volume control, the above is not necessarily optimal on "normal" systems...

What recipe do you use for the speakers -- if you wish to describe it of course. I understand if you don't; the matter interests me as the mid-upper frequencies amp I use is wide bandwidth and I have to be careful....
@ Rower30, It seems charles1dad explained to me what was really being said here,thanks charles1dad!,Rower I am sorry that I misunerstood you,kinda hard tring to understand the word data you posted,LOL!,you do have nice cables!supriseing!,I get tired of being knocked around for having some of the best cables available by non-cable believers,Taralabs zero gold i/c,omega gold speaker cables,Rower30 I did not spend this kind of money for my cables to be a trophy of some sorts!,these cables sound simply amazeing!,they make my equipment sound as if I paid 5 times more than what I did!,Happy listening!
These are my general observations from the physics of how all this works. I like repeatable conclusion backed by calculation as that's what physics is, the real world reduced to numbers (with some guesswork even in those!). But, It's at least a common ground for advancement. I just have a hard time with guessing about stuff. I’m open to repeatable, measurable calculations. Since cables are complex superposition of materials and relationships, with each selected or calculated on its own, the final sonic results that are derived are somewhat a black art, no argument there.

Gregm - The skin depth is one of those, when do you stop, arguments. The smaller the wire, the more consistent the current in that wire at all frequencies. It can, in theory, never be the same except at DC. But, lets get real, it can get darn near the same (can't hear it anymore) with numerous small wires. practical reasons usually mean 23-24 AWG as it gets terribly hard to manage more wire than that and not destroy the capacitance or inductance balance. All those wires are trying to hurt the design EXCEPT for skin depth. This is a somewhat an evil business. Every variable is a cancer to the other! A speaker cable is a balance of many attributes, but the overall balance should fall into an optimal compromise. No, they all won't be the same. If you change any one element, the overall relationships all have to move. The physical relationships of the wire and materials result in the blended finished electricals. The compromises made are EVIDENT and KNOWN by the designer, though. This isn't guessing.

So the optimal gauge is going to be at LEAST no bigger than the radius of the wire at the highest frequency of interest. 20 K is about 18-mils. This is just the definition of skin depth, though (37% current differential at that frequency). How small (reduce the current differential even more) you go is going to be locked in by DCR requirement that will rise as you try to optimize one attribute, (forced to use more small wires!) and how far you think your ears can perceive the skin depth issues. Don't rob Peter too much to pay Paul! BALANCE is the key for an overall nice cable. Nothing I have posted here is a secret other than physics we don't understand to put into numbers. But, we have plenty we do understand that can leverage to make better, more logical, cables.

Audiolabyrinth - Buy the sound, yes, not the price. OK, they might be expensive, they might not be. It all depends on what that "differentiation" cost you! Be careful to avoid "trust me" engineering as what you hear, is more than likely the true basics being correct and not the snake oil applied after the fact. Nothing wrong with snake oil, I suppose, as long as the fundamentals are correct. But, many a cable is JUST snake oil and expensive…and sound poorly.

I look at good sounding cables this way, if you have even 10K in a system a $2,500.00 cable that really sounds good to you is about as cheap an upgrade as you get in audio now-a-days. Yes, it's expensive, but can you beat the sound improvements for the price paid? Here is the BUT part, LISTEN to the cables and try to ignore the price and "packaging / marketing". If the fundamentals are there, the cable should sound pretty nice, as the real world physics will allow it to. You can't cheat Mother Nature. The same relationships are in EVERY cable.