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Speaker wire - another fine theory
On 20 Sep 2003 15:15:37 GMT, (Bob-Stanton)
wrote:
(Stewart Pinkerton) wrote in message
While this is all true, the reality is that most speaker cables have a
characteristic impedance of 50-100 ohms, and are connected to a load
of less than 8 ohms driven from a source of less than 1 ohm. To a
close approximation, this *is* a shorted termination.
But Dick made the *general statement* that as the spacing increases,
the inductance increases. This is not always true.
For example, if the cable has a characteristic impedance of 4 Ohms,
and if the loudspeaker load is 8 Ohms, the amplifier will see a
resistive /capacitve load.
There is however no such cable on the market, and that would in any
event be an absolutely extreme construction of no sonic merit in
almost all situations (long runs into certain electrostats being the
only exception). Indeed, the *only* occasion when such a cable would
make any kind of sense, is precisely in that situation where the load
is *less* than the characteristic imepadnece of the cable at high
frequencies.
For the above case, 20 ft of cable, at 20 kHz, would be 7.98 -j 0.031
Ohms. If the wires are seporated a little, the cable's input impedance
becomes *less capacitive*, not more inductive. One can *not* make the
general statement, that as speaker wires are seporated they become
more inductive.
One can, for normal constructions of two spaced conductors.
--
Stewart Pinkerton | Music is Art - Audio is Engineering
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