Speaker Cable Faceoff 2 - Measurements Part 1

As we indicated in Part 1 of our Speaker Cable Face-Off series, speaker cables have become one of the least quantified and objectively measured/analyzed audio products in the audio marketplace. Many cable vendors and forum cult hobbyists insist on the abandonment of measurements and engineering truths in favor of subjective listening tests in hopes that the listener will think they hear a difference, even if none exists, to justify their unproven claims and sometimes extravagant prices. The belief set forth by these "cable soothsayers" that "you can't measure it" leaves open the avenue of convincing prospective buyers of the differences in product by pseudo-science, clever marketing ploys, and sometimes, just blind faith. Audioholics on the other hand is not a faith-based website, nor are we "cable soothsayers". We believe and cherish objective measurements and feel they are the first step in developing and/or analyzing a high fidelity product. If a product measures well, and the measurements are applicable to its corresponding fidelity, it will usually sound good, however the converse is usually not true unless one seeks inaccurate audio reproduction of music. With that in mind, we have analyzed twelve (12) more brands/models of speaker cables ranging from as little as $0.46 / ft to $500 / ft. Don't let prices fool you however, as in many cases, cables especially, price doesn't always dictate quality.

Note: The bright yellow highlights represent the frequency range at which skin effect is responsible for at least a 40% increase in AC resistance.

Cable Measurement Test Set-Up Notes

All measurements were conducted using a properly calibrated WAYNE KERR Precision Magnetics Analyzer

All of the above measurements were completed on a fully calibrated and certifiedModel# 3260B. The 3260B was calibrated for full bandwidth. The measurements and calibration process were repeated twice for consistency. All cable lengths were between 10 to 20 feet and divided by their length for a normalized per foot measurement. Special care was taken to ensure solid contact was made with these cables when all Rs and Ls measurements were taken by using compression.

At low frequencies the results illustrate Rs being lower than Rdc, which is inaccurate, as Rs tends towards Rdc as frequency approaches zero or DC. The LCR measurement derives Rs from signal phase and amplitude, while a DC meter measures exactly what it is looking for, thus this discrepancy is likely due to a meter resolution issue, as the meter in AC mode does not sport the high accuracy it would in DC mode. The cable should ideally be modeled as multiple parallel resistors, and those resistors treated as a lumped element in series with an ideal inductor. Each resistor is a frequency dependent element, and the inner ones fall out as the frequency increases. It is important to note the difference in measuring techniques, and caution the reader not to attempt to derive any relationships with the two numbers, as the absolute accuracy between the methods has not been established. However, the rising trend of Rs vs frequency is indicative of increased Rac due to skin effect and should also be noted.

Note: Skin effect, cable dielectrics are not shown in this model but have been accounted for in the Rs,Ls and Cp measurements.

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AC Resistance (Rs) / ft vs. Frequency of Various Speaker Cables

Inductance / ft. vs. Frequency of Various Speaker Cables

Capacitance / ft. vs. Frequency of Various Speaker Cables