7
The ideal conductor would have negligible resistance, inductance and
capacitance. The table below shows how a few actual speaker cables
measure up.
Cable
Ω
s/ft
pF/ft
µH/ft
12 ga.
0.0033
24
0.21
14 ga.
0.0048
17
0.13
16 ga.
0.0079
16
0.18
18 ga.
0.0128
28
0.21
Capacitance is considered insignificant in each cable because its effect is
well out of the audio bandwidth; inductance can be decreased (at the
expense of increased capacitance) by keeping the conductor pair closely
spaced.
How long would a cable have to be before inductance effects would
impinge on the audio spectrum? Approximately 300 feet of 12 gauge
would be required to establish a corner frequency of 20 kHz with an 8
Ohm loudspeaker. As you see, inductance is not a problem for most of us.
