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mech986
11-30-2010, 12:33 PM
I picked up a sub cabinet with a JBL 2226H which seems to have been stored too long as the spider has sagged inward statically offsetting the voice coil, cone and pleated surrounds. The spider is not level but also offset inward towards the magnet.

Does anyone know of an appropriate way short of a spider replacement or recone to reset the spider or surround - I'm thinking heat (oven? hair dryer, heat gun), solvents, exercise via sine waves, static offset in other direction using spacers from frame to cone, storage with cone facing down, etc?

There must be a way to fix this without redoing the whole driver.

Bart

subwoof
11-30-2010, 02:55 PM
That is caused by high powered operation in an improperly tuned box - that cone is WAY too stiff to offset no matter what position / length it's been stored.

Once stretched, the spider and surround will remain that way BUT one trick I use if you suspect it was just a temp issue that offset the cone:

Get 4 empty toiletpaper rolls, crumple and add a full papertowel in each and slightly flatten.

Put one of these between the cone and a frame rib on equal distances and slide towards the outside rim to adjust the "push" Be careful of the leadwires.

Then wait. and wait.

If the lead wires are copper colored, the cone predates the 1992 change to aluminum and you would be better off reconing it anyways.

sub