Hello and best wishes for 2005 !.

I have to recone one of my Le15A ( I have 2 ) and I can't find any reason why this speaker does not work .
The Le15 began to resound badly more and more , I know he is well protected so it was not hurt and I did not use it so loud !!!, last reconing was 10 years ago .

What can be the reason ?

thank for answers .
Gerard