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
Almarg,

Yes, you're input is spot-on. One is a goof, the other is more accurate to the current gradient effect based on skin depth, and the last is I can't count zeros! It would be nice to be able to EDIT as the author to improve accuracy, and make it easier on the reader to get the right info fast. Well, as fast as my stuff will allow (ya, I hear you...shut-up already!).

I'll admit the effects of skin depth are "real" based on calculations but the audible nature is hard to pin down EXCEPT that I have used IDENTICAL R, L and C cable on purpose and listened to designs with little regards (four wires) to no regards (two big wires) for skin depth. Those with more exceptional regards to skin depth at 12-20 wires in each polarity had improvements that were immediate. So I have to look at the overall design, and try to figure out what is going on as you use multiple wires. What is really skin depth management and what is something else? In theory, it can't be PHASE as the capacitance is VERY low (less than 30 pf/foot)in both designs.

Calculation say that capacitive roll-off first order filter PHASE shouldn't be audible, either, with reasonable capacitance. But, a superior design can simply bypass this effect to make it a none issue and still get sub 0.150 uH/foot inductance.

I agree, and point out, that speaker cables between a speaker / amp combination will sound more or less better moving from system to system. But, I also point out that "I" have not had an exceptional cable fall in my rankings switching systems, from dynamic drivers to electrostatic panels.

As to wire coatings and wire...has anyone heard tough pitch copper (~1500 grains per foot) verses OFC copper (~300 grains per foot) verses functionally perfect copper (~30 grains per inch) and single crystal copper in the exact same design? Go ahead and add verses silver plated to any type. I'm hot on the trail of trying to do just this between at least two copper types if I can.

Yes, I added copper quality, but tend to throw it down the list as good design eclipses what the copper supposedly brings to the table. Copper seems to be a knife in a gunfight. Yes, it can get some of the job done if the heavy lifting is already out of the way.

This is facinating stuff, in that it's like an unsupervised free for all. Like the light out in the cafeteria...seriously fun, but when the light come on, the mess has to be accounted for and blame placed on the right suspects. Let's get the light on, shall we?
Rower30 wrote,

""...The high end has known about wire directionality for at least 10 years; isn't it about time for everyone else to catch up? ..."

"In my opinion, no it isn't. There isn't any proof to catch-up to. Is the "audio" community the only place where sinusoidal information is transmitted? Why has no other scientific discipline, with far more fragile signals than audio noticed this phenomenon (well, it would be a phenomena if there was any true evidence it existed) and hasn't taken advantage of it?"

Like a lot of things in this hobby there might be no proof. But if you're looking for evidence you need look no further than the testimonies of customers of aftermarket fuses who have experimented with the direction of fuses and have reported their results. It's because directionality is now part of any intelligent design that so many high end cable and fuse manufacturers control the fabrication of the wire in order that the directional ARROWS that appear on their products show the correct orientation. It wasn't that long ago that the owner of HIFI tuning (were his the first aftermarket fuses? I think they probably were) maintained that his fuses were NOT directional, even in the face of his customers' findings to the contrary, and that no matter which way his fuses were inserted they would eventually "settle in" and work themselves out. In the meantime, the owner of HIFI Tuning has recanted and his fuses now come with little arrows to point the way.
More noise and obfuscation from GEoff as usual to soften people up so they might better accept his nebulous products while running around in his vendor-induced haze. Plus he has the nerve to do it in thread that is otherwise soundly based in practical interpretation of actual facts by those with some good real knowledge to share. These are open forums, but that really irks me and I am free to say so as well!

If people want to spend time figuring our which direction their stuff sounds better in more power to them. I would only add that I would recommend doing some homework and addressing fundamentals that are known to make a difference for concrete reasons first. Like optimizing speaker placement and orientation first, for example. That's the only reasonable way to go about anything.

Its an old story but of course people saying or thinking something works and even a vendor marketing something in of itself means nothing really.

For the records, my MIT ICs are supposedly directional in that the network boxes are at one end and there are arrows indicating proper orientation. SO that is the way I hook them up. It even makes sense to me that these are "directional" in that the two ends are CLEARLY not the same. I have had them hooked up both ways. Was there a difference? Maybe, but I could not identify. So I follow the directions and loose no sleep. IF there are no directions provided indicating a direction, like with the DNM ICs I also use, I loose no sleep. Somehow, it all worked out and everything sounds good.
Mapman wrote,

"For the records, my MIT ICs are supposedly directional in that the network boxes are at one end and there are arrows indicating proper orientation. SO that is the way I hook them up. It even makes sense to me that these are "directional" in that the two ends are CLEARLY not the same. I have had them hooked up both ways. Was there a difference? Maybe, but I could not identify."

Mapman, have you given any consideration to visiting an audiologist?
The skin effect numbers cited are incorrect. In the audio band, it is necessary to use the bessels for accurate numbers, the exponential approximation is incorrect.

All t lines obey the simple equation LC =1034 DC when the t-lines are constrained, such as coax, high aspect ratio striplines, and high paircount magnetically orthogonal twisted schemes such as cat5e multi's.

Parallel run conductors will use LC = 1034 EDC, the effective dielectric constant being about 4 to 6 for zips.

The prop delay argument is inaccurate when load and source impedances are very low in comparison to the line impedance.

To answer the question "why are we going in 300 or more directions?" That's easy. The misconceptions which abound confuse the issue.

jn