On Fri, 19 Nov 2010 17:05:36 +0000, N_Cook wrote:

Meat Plow wrote in message
news
On Fri, 19 Nov 2010 13:01:19 +0000, N_Cook wrote:

Bass driver giving off a noise like frying bacon of fairly constant
level compared to varying audio level. They had used epoxy glue and
soft contact glue at 2 different stages of fixing the spider to the
frame. Epoxy had squeeged into the interior forming beads of solid
epoxy up to about 10 mm long by about 2mm that had later broken off
and was rattling inside. So gummy/soft glues only is the lesson . As
there is always bits of sub-mm aluminium oxide etc , but greater than
air filter mesh size , inside speakers, that don't seem to make any
humanly observed rattling interference noises , anyone any idea what
is the size that becomes intrusive ?. In the core that is , not
staples etc on the outside. RoHS stickers all over and all sorts of
other problems in the cab but not PbF isssues (this year)

You want to know the size of a particle that could cause a rub between
the VC and the magnet structure core? Is so I can't imagine it would
take much knowing the tolerances around the VC are measured in the tens
of thousands of an inch. I've seen several of these type and guitar
types get re coned living near an individual who did re-coning for a
living. Some of the shims used while gluing especially in a studio
monitor speaker like a Tannoy I saw get re-coned looked to be around
1.5 mil or slighlty more.



--
Live Fast, Die Young and Leave a Pretty Corpse



These bits were rattling around in the interior space not passing
through the air filter gauze or getting graunched in the vc gap.
Demounted spicer and cone and for "reconing" this one I used 3 slivers
of credit card, hardly thou/mil sorts of dimensions.

I guess it's up to the person doing the re-coning as to what tolerances
they prefer.



--
Live Fast, Die Young and Leave a Pretty Corpse