DaveM wrote in message
...
"N_Cook" wrote in message
...
Again 1m length , ps set for constant voltage and unlimited current.
Set V for 0.5 amps , 2 flats and no change, set for 1A and 4 flats
added, no
change ie less than 0.01 amp change, if any.
Set to give 1.7 amp and varnish burnt off. So no further forward.


--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/




All your testing seems to have verified that the formula for resistance
vs.
cross-sectional area does work. No matter how many 'flats' you make on
the
wire, you haven't changed its resistance. The small amount that it
changed can
easily be contributed to variations in meter connections and/or minute
changes
in length due to the squeezing of the wire to make the 'flats'. Barring
any
crystalline structure changes in the metal itself, so long as the
cross-sectional area and length doesn't change, the resistance doesn't
change.

I suggest that the speaker winding that you're trying to diagnose failed
because
of metal fatigue, possibly due to loose mounting, broken adhesive or just
an
imperfection in the coil at manufacture.

Time to move on?

--
Dave M
MasonDG44 at comcast dot net (Just substitute the appropriate characters
in the
address)

Life is like a roll of toilet paper; the closer it gets to the end, the
faster
it goes.




If it was just a one off , then fair enough. But 2 separate Mackie amps with
the same problem in the same 2 squashed percent of the wire of the speaker
voice-coils ?

--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/