[net.audio] cables for 250 watt amp

bryan@ihuxf.UUCP (05/02/83)

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Path:burl!spanky!ihnp4!ihuxf!bryan
Message-ID:<366@ihuxf.UUCP>
Date:Mon, 2-May-83 13:39:46 EDT
Organization:BTL Naperville, Il.


I think the wire you mentioned is No. 6 7 strand wire.
The D.C. resistance of it is .042 ohm per 1000 ft.
This means if you place a speaker 50 feet from the amp,
at 250 watt level the cable will disapate aprox. 1.5 watts,
which will have no effect on the sound quality. By the way
if you were ever to look at the cables inside the speaker and
the connectors used it would suprise you as to how "small" they
are (usually 18 or 20 guage.)
				Bryan K. Delaney
				ihuxf!bryan
				btl naperville, il

emrath (05/08/83)

#R:ihuxf:-36600:uiucdcs:22700018:000:855
uiucdcs!emrath    May  7 14:09:00 1983

I think you're off by a decimal point or something on that cable
resistance estimate. My table shows gauge 0000 (quad-aught) copper
to be .049 ohms per 1000 feet  (.16 milliohms/meter, let's think about
moving this archaic country into the metric system!)
No. 6 copper is shown as .395 ohms/1000 ft  (1.3 mohms/m).
These numbers are for solid wire, but I believe stranded wires are
gauged such that a stranded wire has roughly the same resistance
(same order of magnitude, anyway) as solid wire if the gauges are the same.
Is this true?

Sorry this doesn't have much to do with audio, the previous comment
about wire heating vs. total resistance is the important point. Both
power and voltage drop should be kept low enough. For more than a meter
or so, the voltage drop constraint wins, for short distances the power
drop (wire heating) constraint wins.