Speaker Cable : Special Points
Speaker cables need a particular mention as they do affect the sound of loudspeakers. This is because cable has capacitance, resistance and inductance that will react with the capacitive, inductive and resistive elements of the speaker crossover and speaker drivers. The thicker the gauge of copper, the more strands and the better the insulation of the cable, the better the speaker will behave as these combine to allow the amplifier to get more immediate control over the speaker components by raising its damping factor. “Damping Factor” refers to the ability of the amplifier to effectively “dampen” the natural “Back EMF” oscillation effects from loudspeakers (badly damped speakers sound “woolly” and undefined). Remember also that each strand is an individual “resistor”. Ohm’s Law shows us that adding resistors in parallel with one another lowers the overall resistance of the total network. Thus more strands can help with overall “resistance per metre” of the cable too. This is another important factor when using long lengths. The lower the resistance per metre the less effect it has on transmission, especially when you are pulling large amounts of current!
The human ear is immensely sensitive to phase inaccuracies. This is because although we hear up to 20kHz, in order to pinpoint sources of sound to the accuracy we do, our brains discriminate phase timing displacements between the ears in the realm of around 500kHz. (This is also explains why we ‘hear’ digital jitter). The dielectric material can have a large influence on phase linearity.
Not only do fine strand cores give much better phase accuracy and high frequency precision, they are flexible and long lasting. Thick strands cost less but are stiffer and have a shorter life span.
As outlined above, speakers require a cable gauge appropriate to their current draw – the speaker manufacturers generally recommend a suitable gauge. However, the cable gauge must be increased as the distance between the speaker and amplifier gets larger.