Cables sometime raise two kids and let the third one run wild. Low R and L, but high C as an example. To get low capacitance in a design (you have to hold the design exactly the same) inductance will go in the opposite direction. If it goes too wacky, it eats up amplifiers and / or requires Zobel networks to offset capacitance just like power-line power factor correction circuits. Fundamentally superior designs have low R, L and C from the get go. You can't force too high cap to go lower as it pushes inductance up. The design is simply poor. More paper, start over!
With compensation you no longer have a cable per say, but a circuit. One is useless without the other. Many do indeed market circuits. This isn't completely wrong, but it isn't an ideal "cable" either. Take away the Zobel network or "pole articulation filter(s)" and the effort is lost. So, those products are a different breed than cable design, and more expensive as they extend the margins on both fronts.
Some even try to say they "separate" the magnetic fields and electrical fields into different areas of the cable to improve the sound. I'll use Ebm's comment, "Say what??Dude??". This is impossible, as one needs the other to exist. They are tied at the hip like capacitance and inductance. Unless we move to planet ZEN, this will always be so. Not sure about ZEN, actually, has anyone been there except in the game?
The key concept to understand on fields is that the two fields take away energy, and thus the signal. They don't come from anywhere, and they don't go to anywhere instantly. They steal away energy to exist. This is distortion that is required in the real world when we pass current in two wire separated by distance, like it or not. There is no perfect cable, but there are GOOD DESIGNS.
Why do we have to live with imperfect cables? Here we go (those that don't like longer posts should leave now).
Knowing what a perfect conductor is allows you to recognize a good compromise that fits the world we live in. I was going to put this in the initial thread but I think I wore myself out writing it!
A perfect wire is / has / can;
1.0 Has ZERO resistance and thus loses no signal amplitude. This is a benign distortion in that it is linear. So in reality ZERO resistance isn't really critically important UNTIL you include the speakers X-over. Now it's a problem.
2.0 Is infinitely small. There is NO skin effect as ALL as current across ALL frequencies are IDENTICAL. Well, this is a tough one so we have to gauge (pun intended) the wire to our frequency pass band. A wire has to exist in reality, but to what size? The dimensions are limited by the designers ability to manage many wires.
3.0 Carries energy in BOTH directions at the exact same time. Umm...this is a short circuit in reality. But, if we could do that, the magnetic / electrical fields would be equal and opposite. We would not waste energy creating fields around the single full duplex audio wire. Just think infinite transient response...with a little help from a vacuum, that's next.
4.0 The dielectric would be a vacuum so we have ZERO capacitance and velocity would be 100%. Great, we just got rid of phase effects caused by band-pass filter characteristics and rise time voltage distortion.
So, we have a perfect audio wire, in our mind anyway. And, that 's a good thing when shopping for cables.
We all would like this impossible to make wire. The next best thing is a ZIP cord, many feel. Well, if you can make a zip cord with 24 AWG wire, keep it short so that the DCR doesn't influence the speakers response, and use a good dielectric they can sound pretty darn good...and they should as they obey all the required tenants of a good cable. Except that they have too high a DCR in any meaningful length and / or speaker efficiency. Once you try to make a ZIP cord bigger, it goes to hell. DCR get lower, but BIG wire loses skin current management, stranded is a bad screen and gets worse over time. This forces many smaller wires... that are hell to manage with all those wires increasing capacitance. A capacitor is a dielectric on each side of a conductor. Make it LONGER or WIDER and the capacitance goes up...a LOT. It's a squared law increase, so many wires is hard to do, not impossible. So here we are with much larger AWG requirements and about 36 wire.
A clue to excellent B and E field management is if the overall cable has lower inductance than a SINGLE "unit" used in the cable. This demonstrates, with out magic, that the design leverages superior field cancellation. You can't fake it.
Another issue to some is RF. Electrical fields leave the cable perpendicular to the surface of the wire, always, and cancel at ninety degrees intersection to other like electric fields. The problem is, you can't go "forward" with one wire stuck at ninety degrees to another. That's an "X"! So, you try to manage RF by as good a cross-field cancellation as you can with passive field cancellation through reasonable wire crossings of LESS THAN ninety degrees. Remember, the magnetic fields are cancelled by the close parallel proximity of each wire where closer is better, and the electric fields cancel by cross-field interaction cancellation. A design has passive RF cancellation or it doesn't.
Overall shields? YIKES! This pretends we ALL HAVE A PROBLEM (we do, just not in our systems) and uses a another less bad, but still bad solution...a shield. This is still bad as it drives up capacitance to unnecessary level UNLESS the second worst problem (a shield) is better than the worst (no shield). If you have no real RF issues, ditch the shield! On a speaker cable the problem is probably egress FROM your speaker cable TO you electronics, not ingress FROM the outside world into your speaker cable.
Another interesting factoid is that a dielectric polarizes by nature (that's WHY it is a dielectric) in about 10 to the minus fourteen seconds! Hey, that's fast. The polarity reversals need little help at audio frequencies to switch polarities. Yes, at HIGH, HIGH and I mean HIGH frequencies in the many giga hertz, the dielectric can lose the ability to keep up. But it’s fastest at 1 Hz and gets slower from there. But at 20 kHz it's not even an issue at all. And, most polarization modes don't even count in audio. Yes, there are about three, and I won't bore you with them all.
So, we never have perfect sound. Every cable will be a fingerprint of its design, more than materials. A good-looking people tend to always look good! The clothes aren't going to fix the major issues with the person’s looks, as an example. Buy the person FIRST. DESIGN, DESIGN, and DESIGN! No, you can't measure all the effects of a system as complex as an audio cable as it lives in the electromagnetic transition zone, and drives an unstable load (speaker) with respect to frequency. BUT, you can segregate good design from bad based on a BALANCE of electricals for truly superior cable. Take those type cables home, and I'm certain that what I've mentioned will perk up to the top of the list when you listen.
Digital cables are more about reflection errors. Lengths are important based on cable bit rate speeds that define the cables worst reflection lengths, called RL or Return Loss. Rise time errors aren't so bad with modern electronics (thank-you 100 Gig Ethernet!) and pretty short leads. If a zero or a one is sent and received, the DAC is the sound as it re assembles the data. Not an easy job, by the way! You never get to hear a zero or a one as they are simply logic "states" that the electronics uses to compile analog data. Digital starts with analog, so it's goal is to not screw that up in the middle between A to D and D to A converters.
Cables I use? I have ONE TYR 2 NORDOST XLR interconnects that is good sounding. I'll use it as a reference when I work on other XLR cables. I've auditioned the NORDOST speaker’s cables. I brought them home based on their good overall DESIGN, NOT the not so good price! But, the fact that the design is solid is weighed out in the sound. The price is emotional. I was looking at DESIGN and the connection so sonic ability. Good cable stays good all the time. You do NOT want to use cables to "tune" your system, especially if you buy them. Make sure they go ANYWHERE with ease. A well-designed neutral cable is what you really want. A perfect cable, for instance, is what we really want, and it does NOTHING to the signal. So if you are really into this for a good DESIGN cable you want an equal hand of justice to weight the attributes just so. I listen for an even tonal balance top to bottom. Trust me, use three or four cables an you'll hear an even handed product pretty quick.
Speaker cables? Oh I have some. You can't buy them.