How to know it's time to change a diaphragm?

Hi all,

I spent the last three evening carefully listening at my 4343's and tweaking placement as to get the best result. The more I was listening the more I was thinking that they do not sound like I think they should. To my ears it's like there's a "curtain" in between the speaker and me. Drivers are fine and working but it sounds like it is missing some air. I'm not sure if something's wrong or not. I was thinking maybe the caps are too old (should I bypass the caps?) or the diaphragms are to tired. Running a sweep tone do not result in anything out of ordinary.
Is there any way to tell by those symptoms what's wrong?

Fred.

PS: maybe it's me and I get accustomed to good sound :biting:

Hey, Phred... ;)

If the diaphragms are original, they are do for a new set. They will fatigue, and be more edgy sounding, is my experience.

Also, what is the condition of the compliance on the 2121 and 2231...? If original they are certainly way overdue, too...

Yes the diaphs are original as are the 2231s and 2121s. I only refoamed them.
I guess it would be wise to change the 2405 diaphs too? In this thread from John Nebel I can see that they aint cheap :(
For now I will live with it until I find some funds.
Is it best to go by a repair shop or can I do it myself? If I go by the shop then I can get them regaussed.

Fred.

It has been said that the new aluminum diaphragms that use the diamond style surround will fatigue faster then the older style "swril" surround. Thought titanium holds up with the diamond surround, the titanium surrounds don't seem to please as many people as the aluminum diaphragms in a home monitoring application.
This is what I learned from other threads on this forum just recently.

Tom

Well, Fred...

You can't go wrong with renewing the diapragms. It is not so hard. You might start with the 2420's and see if there's any improvement. If you get to a point of confusion, post your question - there's plenty of help here.

I certainly noticed an improvement on new diaphragms - nothing that I could acoustically measure, but the 2421B's were smoother - much easier to achieve a nice overall balance.