Meat Plow wrote in message
...
On Sat, 05 Jan 2008 14:12:58 +0000, N Cook wrote:

Stored all the time, in an on the street van, and obvious mold spotting
of
the cones.
Actual problem is 8//8 + 8//8 wiring with 1 driver failing unnoticed in
a
gig and then followed by the other strained one, oddly at low level
output,
in practise session.
Well I assume that is the scenario.
At least I can bypass the failure pair with some high W droppers for
them to
practise next week, before replacing properly.

Could dampness have played a part in the failure?
Owner obviously handles the cabs with respect , so I have to believe
that he
does not overdrive them (from the original matching bass amp ) - blurb
says
600W cab

Dampness as in high humidity isn't a likely culprit. Voice coils don't
corrode or host molds. Did you inspect the magnet structure for corrosion?
There is a remote possibility that the magnetic pole inside and around the
voice coil could corrode but I seriously doubt it would cause a failure
that couldn't be previously detected as a rub. My guess would be either a
defect in the driver or the cab was overdriven and the client isn't being
honest. I used to see that all the time when I worked on a lot of amps and
cabs.


Agree but I won't be inspecting the voice coils until after replacing the 2
failed units. Reassembled with a number of W/W droppers in there for the
moment.
Moving the cones/feeling by hand shows no grittiness or scratchy noises so
no burst coils, no burning smells around them. There is a few Mohm across
one of them. Other than they have copious grey mold spots on the outer face
of the the cardboard, they and skirts etc look fine.


--
Diverse Devices, Southampton, England
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