Cable Conditioning...how and why

How and why of cable conditioning

All cables consist of some metallic conductor surrounded by an insulated coating intended to prevent contact with other conductors or outside surfaces. The conductor and the coating form a distributed capacitor whose actual numerical value varies with the type of insulated coating and the length of the cable. Typical real world home audio cables are usually in the 10-25 pF per foot range. In addition, the very existence of the conductor also forms a distributed inductance that varies with the length of the conductor and physical configuration/geometry that the conductor takes. A conductor wound into a coil, for example, will exhibit a different value of inductance than a straight conductor.

As various signal voltages are applied to the conductors, the insulated coating (dielectric) will have its electrical characteristics altered. At the molecular level, the electrical charges will redistribute themselves according to the applied signal thereby polarizing the dielectric. This in turn will have some noticeable and measurable effects on the signals passing through the cable. The effects range from not being noticeable to being very apparent depending on the signal frequency components and amplitudes and on the quality of the reproduction equipment and system.

This polarizing of the dielectric gradually becomes rather stable taking on electrical characteristics influenced by the average of frequencies and signal levels passing through the cable. As this happens, the influence on the passing signal no longer becomes random and attains a stable state reducing or minimizing any artifacts caused by the cable. The object of preconditioning is to stabilize the cable dielectric prior to using the cable for serious listening so as to minimize any detrimental effects of the non-polarized dielectric. 

All dielectrics will gradually become depolarized when no longer exposed to periodic signals. How long this takes will depend on the quality of the insulation. You may have experienced the effect yourself when you've taken a long vacation only to return to your Audio reproduction system to find that the sound has seemingly changed. You just can't put your finger on it but the quality of the sound is not what you remember. After listening for a period of time, the old quality seems to return, or maybe you think your ears have simply readjusted. You are likely hearing the result of the cables settling in once again.