Help with ProAc Tablette 2000 Repair

[BarakaBloke]

I'm repairing the bass/mid driver from a ProAc Tablette 2000. It has a
blown voice coil and the voice coil/spider has torn away from the
cone/dust cap.

I've started by removing the cone/surround. The surround came
away from the basket surprisingly easily just by lifting it away from
its weak glue at one point and working around the edge.

The spider seems to be stuck much harder though. Can anyone
recommend a way to get this off? Solvents seem like the best bet to
me.

I'm hoping I'll find that the voice coil is wound from round cross
section copper wire rather than square or aluminium wire. Does
anyone know? The driver is labled:

CA17 RC/TV-V
H976-08ohm
Made in Norway 42/99

Most people seem to use shims to hold a voice coil in place while
re-gluing everything, but this will mean damaging the dust cap,
which I'd really like to avoid!

I've also read of people using a small battery across the speaker
connections to hold the voice coil in place, but does this really
work?


BB

[BarakaBloke]

Any helpful info gratefully received (see first post)!

---------------------------------------------------------------
Meanwhile, here's a couple of ideas I've had:

Shims: When re-gluing everything why not shim the voice coil from
the outside instead of the inside so you don't have to take off the
dust cap? Would that work? Anyone tried it? But I'd rather use the
low voltage battery method, if it works. Anyone tried that?

I'm wondering if the publicly available SEAS CA17RC would have the
same moving parts as the ProAc CA17 RC/TV-C? If so I could strip
out all the moving parts from one of those and install them in my
faulty ProAc. It would be stronger as well as saving time and effort.
Any thoughts?

Photographs: I've been taking photographs since I started this
project. Would anyone care to see them? If so, what's the best
way to post them?

Thanks,

BB

[BarakaBloke]

Here's an update on my tests with solvents on
the glue holding the spider down:

I was able to remove samples of the glue from around the outer
edge of the spider. I left sample soaking in Acetone, Methylene
Chloride, and Paint Brush Restorer.

Methylene Chloride and Acetone caused the glue to swell and
become weak, but acetone cause visibly more swelling.

The Paint Brush restorer actually dissolved the glue completely.

Then I tried all three (also Alcohol and petroleum type lighter fluid)
directly on the spider, but none were successful. I think the problem
was not being able to keep the glue soaked for long enough. There
were two causes of this. Evaporation but also the spider had a
strong 'wicking' effect and drew the solvents inwards towards the
voice coil. I want to avoid any possibility of weakening the joint
between the voice coil and spider so I has to limit additions of extra
solvent.

My plan now is to use gelled Methylene Chloride type paint stripper.
This should solve both the evaporation and wicking problems. I only
hope that the spider isn't bonded together with resin too!



BB

[BarakaBloke]

Tumbleweeds, whistling wind and a lonely church bell rings...

Paint stripper worked fine and in only a few minutes. Repairing the voice coil looks like a lot of work so I'd prefer using a working CA17 RC driver to strip out the moving parts in the hope I'll find they're identical to the ProAcs and I can relatively easily substitute them in.

The part number in the original post above is wrong. It should read:

CA17 RC/TV- C
Made in Norway 42/99

BB