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Nick,Sorry so late getting back to you – been busy building your speakers. aa I checked out LessLoss’ cable info. Looks to me like they’re pretty right on. Their shielding method seems a little funky though. It seems to me that it may “give” when flexed more in some areas than others and that could cause some impedance “bumps” down the length of the cable. I suppose if you treat it gently and don’t move it once its installed in the system, it would be OK. Nevertheless, I think they’re a little “over the top” about the shielding issue, as we all know that there are cables that don’t even use shields and are considered to be pretty darn good. IMHO, basic engineering practices dictate that a good shield is a very good idea though. I just think going to such extremes is a little excessive, especially if doing so runs the risk of degrading the “smoothness” of the transmission-line’s impedance (which is what a cable is).As a little “adjunct” to what they’re saying, I would add the following: They have their “priority list” that outlines factors governing cable performance in order of importance. Seeing that they don’t offer speaker cables, it all makes sense to me. But…if you were going to add them too you would need 2 separate lists, as the criteria for each are different – at least in my mind.It’s all a matter of impedance. With interconnects you’re typically looking at what we call relatively high impedances. The output stages of most preamps have an output impedance of 100-Ohms or higher and they feed into power amp inputs of 10-Kohms or higher. That being the case, the “carrier” of the signal is mostly a matter of voltage. If you were to measure the actual currents that flow they would be extremely small. This means that issues that effect voltage are the dominant causes for concern. In that case, it looks as if the LessLoss guys have it right.If we were talking speaker cables, that’s a considerably different set of criteria so that list would need revision. Power amp output stages often exhibit an impedance of 0.1-Ohm or even less (high current sourcing models). Speakers usually represent an impedance of 2-Ohms - or higher (let’s hope so anyway). Such a condition doesn’t really represent a “flip-flop” of the interconnect case above, as the voltages involved are scaled up a lot too. But…current flow can be increased by 6 orders of magnitude or more. This means we really need to take a look at how current flow affects things.If we have significant current flowing in a conductor, significant magnetic fields are produced as a result. Magnetic fields have a direct relationship with inductance, whereas electrostatic fields are more associated with capacitance and voltages. In the case of interconnects we should be primarily concerned with the dielectric materials used in the cable, as dielectric constants affect capacitance, which affects voltage. Not to dismiss the current issue altogether, rather, it simply moves down the priority list. In that, the LessLoss list seems to be “right on.”For speaker cables, which are forced to handle both high voltages (relatively speaking) AND high currents, capacitance vs. inductance tend to do a “flip-flop” in order of importance. Not by a lot though as in all actuality, inductance issues would only lead capacitance issues (in importance) by a relatively small margin. In my mind, this means cable geometry and conductor materials move up in rank due to the greater importance of resistance and inductance. Conversely, capacitance and hence the dielectric materials used move down a bit, but they certainly should not be neglected or dismissed.As an example of what I would consider a “poor” speaker cable design would be those types that treat each +/- conductor as a separate cable. Such a design permits random spacing of the conductors relative to each other and hence, produces random levels of both inductance and capacitance that the combination exhibits. A “good” design would not permit this extreme level of “user adjustment” of the L/C values, which certainly won’t permit their optimization. This is because the large amounts of insulation used (to cover each conductor) will not permit them to be placed close enough to one another to balance the L/C values (particularly the inductance), which is necessary to achieve the optimal “characteristic impedance.” Such designs will obviously “work” and possibly still sound good – they just won’t achieve the maximum level of performance they otherwise would.Well…there you go – another thesis. I hope I didn’t confuse you or offend anyone by “dissing” his or her favorite cable design. That was not my intention. Please remember…this is just “my” opinion. After all – what do I know? -Bob
Evidently older than dirt has caught up - you had never been at our place when we were on Ridge street.
Robert,Sorry so late getting back to you. Been busier than a one-legged man in an ass kicking contest.QuoteEvidently older than dirt has caught up - you had never been at our place when we were on Ridge street.Wow, if that's true - I guess so! Uh...are you sure? I remember a setting where the system we were listening to was in an enclosed front porch. Well, it was at least at the front of the house nearest the street. It's not a big deal either way, other than the fact I fear I may really be loosing it. The reason being is that I'm pretty familiar with the area. When I was born my folks brought me back from the hospital to the house at... 805 Ridge. Then years later, my half brother bought the house from them. Then years after that my other half brother on my dad's side bought it from the first one. And...nowadays my nephew lives on the corner of McCollom (sp ?) and Ridge! So, I guess you could sort of say I'm pretty familiar with that street. If I'm mistaken then I really need to start taking some new pills - or quit taking the old ones. Take care all!-Bob
I think the core of the problem is that in order to hear the differences a system (by system, I'm including every piece of electronics as well as the room) must have a certain minimum threshold of resolution in order to evaluate the differences
The other problem is that it takes a certain amount of experienced listening to discern differences. The analytical listener is different from the casual listener is different from the musical listener. Knowing what to listen for is not a inborn sense. It is a learned behavior. It takes practice listening to a variety of equipment in a variety of situations. We don't all have the same sense of hearing accuety either. So its not a big surprise that this topic is so divisive and frought with potholes along the aural highway.
Another thing is that how MUCH of a difference will different cables make? Source components, generally, are a much greater determanent of SQ than cables. Cables are a, relatively, minor piece of the puzzle. But to those of us who are interested in the best SQ, still an important piece. Lastly, there are a lot of us who are hesitant to spend a unproportionally large amount of cash on cables relative to the rest of our systems.
The funny thing is that these SP Tech speakers (with a proper front end) makes it so easy the hear differences even in cables.
This is an interesting article with relevance to the original post, make sure to check out the links on the second page.http://www.audioholics.com/education/cables/silversmith-audio-cables-interview
Of course GDS as he is known by, is a really smart and smooth talker, that support himself on the "correct" theory and math...
I for one regard him as a good tech dude... with insight into what he has learned, and found to be measurable...
A very good promoter of the "science clan" you might say...A very very stubborn person...
He's supposed to be treating a waveguide in cylindrical geometry, yet he's using planar equations and assuming there's no variation of E&B transverse to the propagation direction. Thus, this paper only presents standard solutions to an EM wave propagating in a conductor of planar geometry (ie, not a waveguide/transmisison line), not what the author set out to show.
i found it a little unexpected that he treated the conductivity/permitivity as scalar constants. Maybe this is okay at audio frequencies (it's not cool in plasma physics, but the frequencies are much higher).
He makes a comment towards the end that Bob paraphrased, "I wonder if current vortices can result, like whirlpools in a stream of water." This comment really makes me wonder about this guy/article. What he's discussing sounds like an eddy current to me. Eddy currents are the source of the skin effect he spends a good deal of the paper discussing.
To actually see eddy currents in the examination, he'd need to relax his problem to include variations in the r and theta direction (ie, actually do the problem he set out to do).
