"August Karlstrom" wrote in message
...
I have read more than one article where the recommended maximum length
of loudspeaker wire is presented as a function of the wire gauge and
the impedance of the speakers, e.g. in the Wikipedia article
http://en.wikipedia.org/wiki/Speaker_wire#Wire_gauge
**Like all such cliams, the Wiki article over-simplifies things. They ignore
the very real effects of inductance, when using long cable runs and speakers
which exhibit a falling impedance at HF (like ESLs). In those cases, the
inductive effects of cable can become quite significant.
I have also heard that output power and damping factor should be
considered as well - a high power amplifier needs a thicker cable.
**Again, it depends on the speakers and the length of the cable.
Are there any studies made about the wire length contra output power and
damping factor?
**It's just maths. There's no real mystery here. The problem with the term
'damping factor' is that it relates to (usually) an 8 Ohm impedance. Hardly
any loudspeakers present an 8 Ohm impedance. A far better term for amplifier
manufacturers to use is output impedance vs. frequency. IOW: The output
impedance should always be specified from 20Hz ~ 20kHz. Many SET and Class D
amplifier manufacturers carefully avoid citing this data for some very good,
albeit cynical, reasons. The output impedance of such amplifiers can easily
reach several Ohms at 20kHz.
--
Trevor Wilson
www.rageaudio.com.au