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
JN, thanks very much for the additional insights! All of which strike me as being highly plausible, notwithstanding the fact that I have never before seen them so stated. And I strongly second the subsequent comment by Corazon.

I would commend to everyone else's attention the related comments you provided in the 2005 threads here and here.

So if I understand your comment above correctly, skin effect is an even less important factor than even skeptics of the significance of that effect (myself included) may previously have envisioned. While the storage and delayed release of energy resulting from cable inductance and capacitance (as distinguished from the effects of "dielectric absorption" that are often referred to in cable marketing literature) are likely to be of greater significance than is generally realized.

Interestingly, I recall that in past threads Ralph Karsten of Atma-Sphere, who as you may be aware frequently posts here under the screen-name "Atmasphere," has mentioned that many years ago various experiments he had performed indicated a correlation between sound quality and the closeness of the match between cable characteristic impedance and speaker impedance. That, of course, does not seem explicable on the basis of RF transmission line and reflection effects, and I had suggested in one of those threads the possibility that what he observed may simply have been the result of the low cable inductance that usually goes hand in hand with low characteristic impedance. I said that in part because the impedance of a dynamic speaker at the ultrasonic and RF frequencies for which reflection effects may become significant is usually much higher than it is at audio frequencies, primarily as a result of the inductance of the tweeter(s). This statement in one of your 2005 posts seems to reconcile it all elegantly:
As it turns out, the point of minimal line storage occurs when the characteristic impedance of the cable matches the load..so, in theory, an 8 ohm speaker would work best with an 8 ohm cable impedance..this of course, is not because of reflections per se, but rather, just simply from the calculations of inductive and capacitive storage...
So the bottom line, if I understand correctly, would seem to be that in the case of a speaker cable, and assuming that neutral behavior is desired, minimization of both inductance and characteristic impedance is desirable, up to the point at which characteristic impedance matches speaker impedance (at audio frequencies), with capacitance also being minimized to the extent that it is practicable to do so without significantly conflicting with those goals.

Although, of course, whether or not truly neutral behavior will be subjectively perceived as optimal in a given system by a given listener will always remain an open question.

Thanks again for the excellent and rarely stated inputs!

Best regards,
-- Al
Please forgive me if I appear to be harping on one aspect of this multifaceted conversation. But, other than the added complexity(?) of perhaps needing a Zobel network to protect the amplifier, if all the other prescribed considerations are met, is there any harm in having a speaker cable with a characteristic impedance that is less than the speakers impedance?
And with that aside for the moment; since most speakers have a varying impedance should one strive to have the speaker cables characteristic impedance match the speakers nominal, minimum, maximum or some other impedance?
@ Jneutron,I like your position here with this post you stated!very realistic and comprehensive,with not to many words that mean nothing!,and the fact you gave help toward the cable industry is out standing!,I am nothing more than a consumer of cables,thou I have been around along time with my own inventions with resonance control and resonance tuning,sometimes science cannot explain everything!,to me if what a person created for sound works and sounds good to a fanbase of consumers than it must sound good and you feel like you are not waisting your time or others!,then there is the fact you claim that you are not immune to learning!,my setiments exactly,however,I will refuse to learn a science that dictates that what I hear does not exsist!,like cables signal flow is irrevelent,It may be possible for some brands of cables out there for this to really not matter,In my situation,a house full of 20 people and my self can hear clearly the difference signal flow made with top tier Taralabs cables!,for someone to state that all cables signal direction is irrevelent is very frustrating,how in the world can they base a finding with a few brands of cables out there and say, this is the way it is with all cables in the industry as a whole?,realisticaly that would take years of an attempt with a conclusion of failure!,the reason would be that most cable brands use different dielectrics,conductors,grounding schemes,the way conductors may be wound,are having no dielectric at all and have a vacume within the cable,the list can go on,I love learning,to me it is humane nature to test what someone claims,if there is no absolution,then to me the claim means nothing!cheers!,happy listening!
I wonder is the impedance matching aspect that has been discussed of value only in theoretical discussion or is there a practical way to realize and assess the potential benefit?

I suppose the best IC would be no IC. Integrated devices like integrated amps, with or without DACs, and traditional receivers are best suited to accomplish that. I wonder if there are ones that focus on the concepts relating to ICs discussed here to "connect" the sections of an integrated device optimally? Or does the nature of an integrated device, ie close proximity of components to connect together in the same chassis just render the issue of how to connect best practically moot?

If there is a concrete significant benefit for an optimal IC versus those actually used in practice, that would seem to argue that integrated devices have a distinct advantage in that regard, ie everything "integrated" optimally by a designer out of the box so the user does not have to be concerned.

That might be one reason to buy an integrated, though close proximity of components in a single chassis is probably a double edged sword and the potential for noise and interference a much bigger issue that works against the goals of optimal performance.

That leaves one with the common path of keeping things separate and having to live with "imperfect" wires to connect everything. Oh well....