From Audioholics Web-site ----
Dielectric Absorption in Cables Debunked
Before we debate the relevancy of Dielectric Absorption relating to speaker cables, and commonly perpetuated by many exotic cable vendors and cable cult hobbyists, let us first define the roll of a dielectric.
According to Wikipedia (http://en.wikipedia.org/wiki/Dielectric) the definition a Dielectric material is an insulator. The ideal dielectric would be a vacuum or infinite impedance. However, real world dielectrics do NOT have infinite impedance and therefore are not perfect. As frequency increases, the Dielectric starts exhibiting shunt resistive losses which can be measured and quantified as signal loss across the termination load. Fortunately for our application (audio) these shunt losses don't begin to surface until frequencies much higher than the audio bandwidth.
At audio frequencies, even the worst dielectrics (IE. Polyvinyl Chloride, aka. PVC / plastic) used in cheap and many exotic speaker cables maintain shunt resistive impedances in the mega ohms or more. When dealing with a low termination impedance of a loudspeakers (usually in the order of several ohms) the dielectric shunt resistance is on the order of 10^6 greater, thus the parallel impedance remains virtually unaffected and we see no losses due to the dielectric at audio frequencies.
Cont'd....
http://www.audioholics.com/techtips/audioprinciples/interconnects/dielectricabsorptioncables.php
Dielectric Absorption in Cables Debunked
Before we debate the relevancy of Dielectric Absorption relating to speaker cables, and commonly perpetuated by many exotic cable vendors and cable cult hobbyists, let us first define the roll of a dielectric.
According to Wikipedia (http://en.wikipedia.org/wiki/Dielectric) the definition a Dielectric material is an insulator. The ideal dielectric would be a vacuum or infinite impedance. However, real world dielectrics do NOT have infinite impedance and therefore are not perfect. As frequency increases, the Dielectric starts exhibiting shunt resistive losses which can be measured and quantified as signal loss across the termination load. Fortunately for our application (audio) these shunt losses don't begin to surface until frequencies much higher than the audio bandwidth.
At audio frequencies, even the worst dielectrics (IE. Polyvinyl Chloride, aka. PVC / plastic) used in cheap and many exotic speaker cables maintain shunt resistive impedances in the mega ohms or more. When dealing with a low termination impedance of a loudspeakers (usually in the order of several ohms) the dielectric shunt resistance is on the order of 10^6 greater, thus the parallel impedance remains virtually unaffected and we see no losses due to the dielectric at audio frequencies.
Cont'd....
http://www.audioholics.com/techtips/audioprinciples/interconnects/dielectricabsorptioncables.php