I quote:
Speaker cables and interconnects represent one of the most controversial subjects in audio/video. Do they make a difference in the quality of the signal being passed from one component to another? Are they worth the price? You will find audiophiles of all degrees of experience and expertise answering these two questions with yes's and no's. Why the controversy? At least part of the answer lies in what we have been told, rather than what we have heard for ourselves. Secondly, it is difficult to define precisely what to listen for when comparing cables, and third, any particular cable may sound quite different with one set of equipment than with another.
During the last year, we began researching some of these questions for ourselves, believing at the outset that cables probably did not make any truly noticeable improvement in sound quality. We were wrong in our assumption, and how!
Cables do make a difference, and in order to see why, it is first necessary to understand the characteristics that affect their ability to transmit a signal.
The "personality" of a cable is determined by three basic electrical properties: resistance, capacitance, and inductance. Resistance is probably the smallest factor, because cables use good conductors (copper and silver). The real culprits in cable transmission are capacitance, measured in picofarads or pF (trillionths of a farad) per foot, and inductance, measured in microhenrys (millionths of a henry) per foot.
Any time conductors are surrounded by an insulator (dielectric), capacitance occurs. You want this to happen with capacitors inside the amplifier, but not in the cables. Depending on the insulator, some of the electrical signal passing through the cable is transferred to the insulator, stored as energy (electrons), then released back into the cable where it causes a degradation in the sound quality. The type of insulator has a direct effect on the capacitance. Various insulators are used in high fidelity cables, and, in increasing quality, they are PVC, followed by polyethylene, polypropylene, and finally, Teflon, which is the best. Usually, Teflon insulated cables are the most expensive, partially because it is a difficult material to work with. Typical values of capacitance with high quality audio cables vary from 6pF to 50pF per foot. Inductance is the property of the signal in one conductor inducing current in another nearby conductor, and inhibiting current flow in the opposite direction. This is desirable in transformers, but not in cables. Since cables usually have two leads, each conducting in the opposite direction to complete the circuit, high inductance can cause the flow of current in one lead to interfere with the flow in the other lead. Inductance values for audio cables vary from about 0.1 microhenrys to 0.6 microhenrys per foot.
Some amplifiers are more sensitive than others to the load that the speaker cable places upon them. The higher the output impedance, the more likely capacitance and inductance of the cable will affect the sound quality. Tube amplifiers are probably most sensitive, since they tend to have higher output impedances (e.g., 1 Ohm) than solid state amplifiers (e.g., 0.01 Ohm). In any case, however, capacitance and inductance values are important in determining how the cables will perform in any sound system.
Cables...
inductance: 0,1 to 0,6PF = 600%
capacitance from 6 to 50MH. = 833%
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