View Full Version : rotten foal in 2420 driver

10-23-2004, 03:54 AM

Last month I decided to look at the diaphragm on my 2420 driver ; when opening the driver I saw the foam glued in front of the diaphragm was rotten and need replacement .

May be if you do not open the driver for a long time you may have this problem , not serious but need to fix ? .

Just an advise may be many of you know already !.


Mr. Widget
10-23-2004, 10:16 AM
Yes the foam in the rear chamber will rot and needs to be replaced. If you were in the states you could order replacement foam from JBL. They still sell it cut for the 375 (2440/2441) which can be trimmed down to fit the LE85 (2420/2421). If I were you I would try to find some new open cell foam that is about 1cm thick. Hopefully you can find some with a psa (self stick) backing on it.


10-23-2004, 11:49 AM
Mr Widget

Well I cut a piece same size and glue it . Just about the same and cost nothing !!!



Tom Loizeaux
10-25-2004, 05:15 PM
Be careful when you put a new foam pad in to your drivers. Be sure they are not too thick, which might make them touch the diaphragm. This would no be a good thing!
When I replaced mine, I used a thin open cell foam (actually foam used as an air conditioner filter) and I put a single layer of felt over it. The idea is to soften down that rear chamber and to disperse the reflections.