View Full Version : 2405 diaphragm replacement procedure

01-24-2005, 07:38 AM
A while back I found (somewhere on the internet) a set of instructions for replacement of the 2405 diaphragm. I believe it was a JBL document (canít swear to it), however, I have been unable to locate it on the JBL site. At the time I found it I printed out a hard copy of the instructions and filed it away, however, Iím at a loss to find that also. Now that Iím ready to replace my non-JBL 2405 diaphragms with original JBLís I would like to find them again. I read the instructions at the time I downloaded them and even opened up the 2405ís and feel pretty confident but a reread canít hurt. Iíve replaced several Altec diaphragms and the process as I remember it is about the same but it would be nice to have the instructions as a safety net and be sure I didnít forget/overlook something. If anyone knows the link or can provide any help I would appreciate it. Thanks.

Rudy Kleimann
08-14-2005, 07:40 AM
Did you ever find that instruction sheet?

Man, be careful! it is all too easy to ruin those diaphragms while installing the phase plug. DO NOT let the phase plug twist while tightening its' hold-down screw. When you finish, run a sine wave sweep from 3K on up and listen for ratlles/buzzez/scratchy sounds. Centering the diaphragm properly can be a bit of a trick on occasion.

BTW-are the aftermarket diaphragms you are removing aluminum or titanium?
If they are any good, wanna sell them cheap? I have a few 2405's and a 2402 laying around doing nothing for want of a diaphragm. Would be worth a few bucks to me to see what they will do with the aftermarket dias.